[MacDV] Using MA-300 mic adapter

[Spud0812 at aol.com]

Hi there,
   I have a Canon GL2 here and am using the MA-300 mic adapter. Im using a 
Sennheiser Me-66 shotgun mic on an overhead boom...my problem...the XLR cable 
fits into the adapter which has left and right inputs, so if I am using only 
a single audio source (as in this shotgun mic) how do I record it in stereo 
on the camera? Is there some kind of cable I can buy that will adapt the mic 
to go into both left and right XLR inputs on the adapter?
thanks! 
Vikki