Here's my fix in case anyone else has the same problem. You have to edit the dynapath post processor. It's in your mastercam directory (C:\\mcamx\mill\posts\dynapath system_10_20...yadayada).
If you add a line in the post processor in the "General Output Settings" section (with the other variable definitions) that says:
prv_workofs$ : -1
then it will output E01$ at the beginning of the code as long as 0 is selected as the workoffset in the planes page of your operation or if its set to 0 in your wcs for the plane your using.
oh and in case you dont know how that works, the default value in mastercam is -1. You can have any offset output if you change the value to the correspinding number of the work offset:
-1 = no work offset
0 = E01$
1 = E02$
2 = E03$
3 = E04$
on and on you get the picture.