irule to pass on User ID and Password

We have a sharepoint site that will house our customer catalogs. Each customer will log into it's onw customized sharepoint site residing on the same sharepoint instance. One of our global accounts wants to do this without having to log in. I know I can set up an irule to allow from a certain IP range (public address of customer)to a specific URL but is there a way to then have the F5 via irules pass on a user ID and password in order to give them read only access to the site?

 

 

We have a BIG IP 3600 serise with LTM and ASM running on it.

 

 

Thanks