XM through the Audio System?

I have an '03 Accord with the Navigation system.  The system is nearly identical to a buddy's of mine in his '04 Acura TSX, and he has the XM radio with it that operates through the system.  I am wondering if it is possible to add the XM service and have it function through my system? 
 
Any feedback would be much appreciated!

Looks like I managed to find my own answer... this feature became standard with the EX-L in 2004.  Too bad.