Come to the Guitar Section, i have videos posted on how to use the 2 together.
The above poster is correct though, You can only have 1 "interface" for Pro Tools at a time. But you can still use an 003 and 11R together, the 11R will act like any other Outboard effects box, not an Interface.
http://duc.avid.com/showthread.php?t=291589&page=2