How to access a webservice that uses Windows Integrated Authentication.

We have a client that created a webservice to identify users.  They are requireing that we use that service to identify users.  I seem to have read somewhere that someone used .net to create the connection and then passed that data to ColdFusion ( or allowed access to the data).  Subsequent searches have not proven to be fruitful.  Has anyone else run into a similar issue?  Know where I can find some information on how to accomplish this requriement?