ISLIKE

ISLIKE(sText, sPattern)
Returns whether a particular string matches a certain pattern.

REMARKS
??

Public Function ISLIKE( _ 
          ByVal sText As String, _ 
          ByVal sPattern As String) _ 
          As Boolean 

   If (sText Like sPattern) Then 
      ISLIKE = True 
   Else 
      ISLIKE = False 
   End If 
End Function 

You can use the built-in COUNTIF function to achieve the same thing.
You cannot use the [] operator in your patterns if you use the COUNTIF function.

For instructions on how to add this function to a workbook refer to the page under Inserting Functions