I am looping through file names with such pattern `name_name-number-name_name.txt`

I need to extract the `number`. 

For example, 

* from `xxx_xx-111-ssadas22` I would get `111`.
* from `xxx_xx-11-sadaesdwsq4443fsd2` I would get `11`

Currently using this but it falls short when there is a number in the name. Also tried a regex but am bad at it.

```
Function FirstDigit(strData As String) As Integer
    Dim RE As Object
    Dim REMatches As Object

    Set RE = CreateObject("vbscript.regexp")
    With RE
         .Pattern = "(^|\\s)([0-100]+)($|\\s)"
    End With

    Set REMatches = RE.Execute(strData)
    FirstDigit = REMatches.item(0)
End Function

```

any idea ?