Changing the location of where outlook gets the users signatures f

I have written an application that queries Active Directory for users
details. The user checks the details and any changes get saved back to
Active Directory. Then a signature is created and stored whereever the
location of the users environment variable %UserPROFILE% points to.

This works great. The problem is that if the user does not have a roaming
profile, they will have to do the process above each time they log onto a new
pc.

Our Outlook currently access users signature via the environment variable
%USERPROFILE%. Is there any way of getting outlook to point to a different
loction so that the users signature can be stored on a server and it wont
matter where the user logs in as outlook will point to this server.

Thank you for your time

Damien