Mapped drives and GPO

I have a GPO dedicated to mapping drives for my entire company on there desktop/laptop; however, I need to add a special mapped drive for when the log into our Citrix infrastructure.  I have created new GPO and in the User section added my Mapped Drive and set it to map to %userprofile% and set the drive letter.  I set that GPO to be applied to certain users when they log into Citrix, but it doesn't map the drive.  I have tried setting the Loopback on that policy to merge, but still not luck.  I've even tried to change the variable to c:\Users\%username%, but still no luck.  And I tried a batch file that works if you run it while logged in, but won't run from the Logon Script portion of the GPO.  I really want to do this with the Mapped Drives function of the GPO, but I'm at a lose.  Any thoughts would be greatly appreciated.