Blender to FBX/XSI issues...

Hello. I am using Blender to create some game models for a game my buddy and I are making. The models are animated, and he uses FBX format and briefly skims over the model in XSI, since XSI shares closer end-results than Blender as to when he puts it in-game (frame count, scale, etc)

The issue we are having is in frames of animation. If I create 50 frames worth of different animations, it is something like a few hundred frames worth in XSI after importing the FBX from Blender. We assumed that we could simply calculate which frames were which, but this is not the case. I’ll give an example:

If I create the said 50 frames worth of animations, and after exporting the FBX and importing to XSI, the frames total 100. Now imagine I want to find the first 15 frames I used in Blender in XSI… We ASSUMED the frames would be 1-30 (considering XSI takes up exactly 2x the frames as Blender in this example) however we realized this is not the case.

We are currently going by what we see visually for movement but it is difficult. If anyone has made a custom exporter script for exporting to FBX that wont jeapoardize frames or if they know of a way to determine which frames are which in FBX, I would appreciate it, thanks.

Any support?