在 c# 中突出显示 Excel 中的搜索词

下面是在excel中搜索单词并突出显示它们的代码。但问题是整个范围被突出显示而不是特定的单词。请帮忙

for (int i = 1; i < xmlnode.Count; i++)
{
    XmlAttributeCollection xmlattrc = xmlnode[i].Attributes;
    object text = xmlnode[i].FirstChild.InnerText;
    string str;
    int rCnt = 0;
    int cCnt = 0;
    Excel.Application xlApp;
    Excel.Workbook xlWorkBook;
    Excel.Worksheet xlWorkSheet1;
    Excel.Range range;
    xlWorkSheet1 = (Excel.Worksheet)doc1.Worksheets.get_Item(1);
    range = xlWorkSheet1.get_Range("A1","A10");
    for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
    {
        for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
        {
            str = (string)(range.Cells[rCnt, cCnt] as Excel.Range).Value2; 
            string[] words = str.Split(' ');

            if (str == text.ToString())
            {
                range.Font.Bold = 1;
                range.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);                                        
            }
        }
    }
}

if (str == text.ToString())
{
  var cell = (range.Cells[rCnt, cCnt] as Excel.Range);
  cell.Font.Bold = 1;
  cell.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red); 
}