Excel regex query returning empty data - regex

Question

I'm using the following VBA code from a related question in my Excel spreadsheet, and when I use it in a cell, it always fails (returns nothing). Even if I call it on a string literal in the function call (i.e. =RegexExtract("ABC1_DEF","ABC[0-9]")), it still fails. I've enabled the "Microsoft Visual Basic Regular Expressions 5.0" feature in the MSVBA application, so I'm not sure why these results are always empty. How can I resolve this?
Function RegexExtract(ByVal text As String, _
ByVal extract_what As String, _
Optional separator As String = ", ") As String
Dim allMatches As Object
Dim RE As Object
Set RE = CreateObject("vbscript.regexp")
Dim i As Long, j As Long
Dim result As String
RE.pattern = extract_what
RE.Global = True
Set allMatches = RE.Execute(text)
For i = 0 To allMatches.count - 1
For j = 0 To allMatches.Item(i).submatches.count - 1
result = result & (separator & allMatches.Item(i).submatches.Item(j))
Next
Next
If Len(result) <> 0 Then
result = Right$(result, Len(result) - Len(separator))
End If
RegexExtract = result
End Function
Edit
I tried yet another function from a separate question, and it just returns #VALUE!:
Function RegexExtract(ByVal text As String, _
ByVal extract_what As String) As String
Dim allMatches As Object
Dim RE As Object
Set RE = CreateObject("vbscript.regexp")
RE.Pattern = extract_what
RE.Global = True
Set allMatches = RE.Execute(text)
RegexExtract = allMatches.Item(0).submatches.Item(0)
End Function

Answer 1

Note you are trying to access .Submatches that stores capturing group values, but you have not defined any capturing groups in the pattern.
If you use (ABC[0-9]) you will get your match with the current function. Else, access the allMatches.Item(i) for full match values and discard the code to get the captured groups.