How to search the whole word in WinForms DataGrid (SfDataGrid)?

public Form1()
{
    InitializeComponent();
    this.sfDataGrid1.SearchController = new CustomSearchController(sfDataGrid1);
}
 
public class CustomSearchController : SearchController
{
    public CustomSearchController(SfDataGrid dataGrid):base(dataGrid)
    {
 
    }
    protected override void HighlightSearchText(Graphics paint, DataColumnBase column, CellStyleInfo style, 
        Rectangle bounds, string cellValue, RowColumnIndex rowColumnIndex)
    {
        if (AllowHighlightSearchText && !string.IsNullOrEmpty(SearchText))
        {
            if (column != null && (SearchColumns.Count > 0 && !SearchColumns.Contains(column.GridColumn.MappingName)))
                return;
 
            var searchText = SearchText;
            string[] metaCharacters = { "\\", "^", "$", "{", "}", "[", "]", "(", ")", ".", "*", "+", "?", "|", "<", ">", "-", "&" };
            if (metaCharacters.Any(searchText.Contains))
            {
                for (int i = 0; i < metaCharacters.Length; i++)
                {
                    if (searchText.Contains(metaCharacters[i]))
                        searchText = searchText.Replace(metaCharacters[i], @"\" + metaCharacters[i]);
                }
            }
 
            searchText = "^(" + searchText + ")$";
 
            //Gets the list of indexes that match with the search text.
            List<int> matchList = Regex.Matches(cellValue, searchText, this.AllowCaseSensitiveSearch ? RegexOptions.None : RegexOptions.IgnoreCase)
                                            .Cast<Match>()
                                            .Select(s => s.Index).ToList();
 
            
 
 
            if (matchList.Count > 0 && bounds.Width > 0)
            {
                StringFormat format = new StringFormat(StringFormat.GenericDefault);
 
                List<CharacterRange[]> characterRangeList = new List<CharacterRange[]>();
 
                //Used 32 as CharacterRangeLength to avoid System.OverFlowExcepion 
                //in StringFormat.SetMeasurableCharacterRanges which occurs if the CharacterRange length is more than 32.
                int characterRangeLength = 32;
                int count = matchList.Count / characterRangeLength;
                int range = matchList.Count % characterRangeLength;
                int startIndex = 0;
 
                if (count > 0)
                {
                    for (int index = 0; index < count; index++)
                    {
                        CharacterRange[] characterRange = new CharacterRange[characterRangeLength];
 
                        for (int i = 0; i < characterRangeLength; i++)
                        {
                            characterRange[i] = new CharacterRange(matchList[startIndex], SearchText.Length);
                            startIndex++;
                        }
 
                        characterRangeList.Add(characterRange);
                        characterRange = null;
                    }
                }
 
                if (range > 0)
                {
                    CharacterRange[] characterRange = new CharacterRange[range];
                    for (int i = 0; i < range; i++)
                    {
                        characterRange[i] = new CharacterRange(matchList[startIndex], SearchText.Length);
                        startIndex++;
                    }
 
                    characterRangeList.Add(characterRange);
                    characterRange = null;
                }
 
                //VerticalAlignment
                format.LineAlignment = ConvertToStringAlignment(style.VerticalAlignment);
 
                //HorizontalAlignment
                format.Alignment = ConvertToStringAlignment(style.HorizontalAlignment);
 
                if (!column.GridColumn.AllowTextWrapping)
                {
                    format.FormatFlags = StringFormatFlags.NoWrap;
                    format.Trimming = column.GridColumn.TextTrimming;
                }
 
                if (DataGrid.RightToLeft == RightToLeft.Yes)
                    format.FormatFlags = StringFormatFlags.DirectionRightToLeft;
 
                foreach (var characterRange in characterRangeList)
                {
                    //Set the range of characters to be measured.
                    format.SetMeasurableCharacterRanges(characterRange);
 
                    //Gets the regions of the measurable characters applied to the string format for the given text with in the text bounds.
                    Region[] regions = paint.MeasureCharacterRanges(cellValue, style.GetFont(), bounds, format);
 
                    RectangleF[] fillRectangle = new RectangleF[regions.Length];
                    for (int i = 0; i < regions.Length; i++)
                        fillRectangle[i] = regions[i].GetBounds(paint);
 
                    var highlightColor = SearchColor;
                    if (this.CurrentRowColumnIndex == rowColumnIndex)
                        highlightColor = SearchHighlightColor;
 
                    // Highlights the search text based on the 
                    using (Brush brush = new SolidBrush(highlightColor))
                        paint.FillRectangles(brush, fillRectangle);
                }
 
                characterRangeList.Clear();
                characterRangeList = null;
                matchList.Clear();
                matchList = null;
            }
        }
    }
 
    private StringAlignment ConvertToStringAlignment(VerticalAlignment align)
    {
        switch (align)
        {
            case VerticalAlignment.Bottom: return StringAlignment.Far;
            case VerticalAlignment.Center: return StringAlignment.Center;
            default: return StringAlignment.Near;
        }
    }
 
    private StringAlignment ConvertToStringAlignment(HorizontalAlignment align)
    {
        switch (align)
        {
            case HorizontalAlignment.Right: return StringAlignment.Far;
            case HorizontalAlignment.Center: return StringAlignment.Center;
            default: return StringAlignment.Near;
        }
    }
}