There are several options for the scripting, everything from a simple
VBScript application up to a separate C# applicaton.  You could create a text
file with all of the URLs to run WSDL against, or you could create a database
or XML file.  Or even write an application to search for the URL in the
existing proxy class, and then use that URL to get WSDL.exe to get the
updated reference.  All you have to do is replace the existing Reference.cs
files with the proxy class generated by WSDL.exe.

Then, as long as the web service interface hasn't had elements deleted
(interfaces can be added to but existing interface elements should never be
modified or deleted - hopefully), you should be able to compile your existing
code with the new proxy classes just fine.

I suggest looking up WSDL.exe in MSDN Library to see how to call the
application and specify namespaces and output files, etc. to make the output
proxy classes match your application framework.