Sub Test()
    MsgBox GetCaption(ActiveDocument.Name)
End Sub

Function GetCaption(sName As String)
Dim sCaption As String
Dim iPos As Integer
    If IsNumeric(Left(sName, 1)) = True Then
        iPos = InStr(1, sName, " ")
        sCaption = Mid(sName, iPos + 1)
    Else
        sCaption = sName
    End If
    sCaption = Left(sCaption, InStrRev(sCaption, "."))
    GetCaption = sCaption
End Function