QTP中字符串替换函数

Function Replace_ex (ExPression, Find, Replace_tmp)
Dim i, j, s , s1
    s = LCase(ExPression) '统一转换为小写，表示不区分大小写
    Find = LCase(Find) '同上
    i = 1
    Do While InStr(i, s, Find, vbBinaryCompare) > 0 '查找
        j = InStr(i, s, Find, vbBinaryCompare)
        s1 = s1 + Mid(ExPression, i, j - i) + Replace_tmp '替换
        i = j + Len(Find)
    Loop
    If i <= Len(ExPression) Then s1 = s1 + Mid(ExPression, i)
    Replace_ex = s1 '输出
End Function