To edit your instrument definitions, right click on the "Line 6 PODxt" internet communication settings file.  scroll down to the list that looks like this

65=65-17A: 
66=66-17B: 

All you have to do is type out the name of the patch like so:

65=65-17A: Zen master 
66=66-17B: my patch

Just put the names you created in there.

To define this in your cakewalk product go to options/intruments.
click on the define button. Then import the Line 6 podxt.ins file you just edited.  
Then just select the podxt on a midi track and select the patch you want. patch change can be created by inserting an patch change.