I believe that the Cap has a straight tapered wing, if so then the MAC will be the chord line half way from the fuselage to the tip. If you put the balance point somewhere between 1/4 and 1/3 the way back from the leading edge on this chord, then transfer these points back to the fuselage side you will be safe enough for the first flight. The weight required to balance the model matters not a jot. If you need it, you need it. The Cap has a reputation as a bit of a tip staller (snaps easily), so do not be persuaded to move the balance much further back, and closer to the 1/4 chord than the 1/3 for that first flight.
Evan.