If you tell us which modelpack is it going about, then we could help (any link?)...

Remember, as long as the format of the model is:
.md2 - commonly used for models which could be used in Quake 2
.md3 - commonly used for Quake 3-models
.obj - commonly used to save geometry only as an universal format.
.md5 - commonly used for models are intended for Quake 4
.iqm - commonly used as a replacement for the "ill-maintained" .md5 and .smd skeletal animation (as eihrul says). You could take that as the animation would be less buggy
.sdm - commonly used for Half-Life models
then Cube Engine 2 can render the model (if the necessary settings are set right).

I would like to refer you to a content I once made and never finished because I'm lacking the knowledge about scripting. The "uploader" contains a prefab of all formats with information of all "known" commands.

If that wouldn't be enough, then I refer to the model-reference of Sauerbraten.