Im having an issue with this myself. I have a steam copy of Jedi Academy. I try importing using the glm import and I navigate to my documents tab in my user account, cause I pasted the assets 01 content in there. I open models, have a bunch of humanoid files in there and main characters form vanilla. I click kyles model.glm and it says error no gla. I think my problem is I dont have my files organized right.
UPDATE: I just put the assets 01 contents (extracted) into my base folder for jedi academy in my steam directory and then C:\Program Files (x86)\Steam\SteamApps\common\Jedi Academy\GameData\base typed this as my base path and its working now.