Consuming a web service in Excel 2003 that requires a certificate
 

I am trying to consume a webservice in Excel 2003 via VBA.

I am using Microsoft Office 2003 Web Services Toolkit to create a proxy
to interact with the webservice. So far so good, but...

The webservice needs a certificate (which i have) but i cant figure out
how to implement it in the code.

I have found an example for Word, but the same code cannot be used for
Excel, as Signatures is not a member of ActiveWorkBook

Code (Word):

Dim sig As Signature
Set sig = ActiveDocument.Signatures.Add


Can anyone help me?