First, this is the Okuma forum, so the depth and breadth of replies may be lacking.
Next, there is a system variable to read the current position of any axis at the moment the line of code is read, but not necessarily at the moment the reset is hit. The machine simply isn't tracking that to my knowledge. Even an Okuma tracks previously executed line, not position when reset. So during a LAP cycle, it tracks what it's last completed sequence is, but not the position within the individual line or movement.
Lastly, if you have a job that requires an insert change mid canned cycle, you're probably better served to run two canned cycles. Keep the same shape, but add a finish stock allowance on the first one that divides the roughing in half, then after that cycle completes flag the machine as needing an insert change. However, if I were you, I'd probably try to get a second tool mounted and figure out how to keep the machine running for one part and not stopping halfway through.
Good luck and maybe post this in the Mori-Seiki forum to see what they can come up with.