Excel VBA 的正则表达式正向回顾问题

Question

我正在运行 VBA (Excel 2003) 并测试正向回顾正则表达式模式。我运行下面的函数但收到以下错误:

运行时错误“5017”:对象“IRegExp2”的方法“执行”失败

我也尝试过设置 re = CreateObject("vbscrip.regexp")
但我得到同样的错误。我已经成功测试了一些积极的前瞻并且它们有效。只是后视是有问题的。我用 Expresso 测试了下面的模式，效果很好。这是VBA特有的 flavor 问题吗？

Function regexSearch(pattern As String, source As String) As String
Dim re As RegExp
Dim matches As MatchCollection
Dim match As match
'Create RegEx object
pattern = "(?<=a)b"
source = "cab"
Set re = New RegExp
   re.Multiline = False 
   re.Global = True
   re.IgnoreCase = False
   re.pattern = pattern
'Execute
Set matches = re.Execute(source)
'Output
For Each match In matches
   str = str & match & " "
Next match
regexSearch = str
End Function

Answer 1

特别是vbscript (因此 vba )。

vbscript不支持lookbehind(负向或正向)