I haven't tested this and forget the source (probably some post on SO).
Function RegexReplace(ByVal text As String, _
ByVal replace_what As String, _
ByVal replace_with As String) As String
Dim RE As Object
Set RE = CreateObject("vbscript.regexp")
RE.Pattern = replace_what
RE.Global = True
RegexReplace = RE.Replace(text, replace_with)
End Function