Function vvv$(t$)
 With CreateObject("VBScript.RegExp"): .Pattern = "^.+(?=\./)"
  vvv = .Execute(t)(0)
 End With
End Function

Sub test()
     Dim z, t$, i&: z = Range("A2:A" & Range("A" & Rows.Count).End(xlUp).Row).Value
  With CreateObject("VBScript.RegExp"): .Pattern = "^.+(?=\./)"
    For i = 1 To UBound(z): t = z(i, 1):   z(i, 1) = .Execute(t)(0): Next
      Range("A2").Resize(UBound(z), 1).Value = z
   End With
End Sub