12? What year is it? I think the number on your module should be somewhere between 1 and 6, inclusive. If you have a 28" draw length I think you have module 3.
If you do in fact have module 3, then your post setting should be 6.5 for 80% let-off, and 6.1 for 65% let-off.
Any of you Bowtech guys confirm this? I'm just going off the 2004 manual and what I know about the Infinity cam.
BTW: Count the first line next to the "L" as the #1 mark. In this photo I have my post set at 7.0.