[Blackberry dev] Eclipse doesn't generate .cod files from an imported .jar file

Question

Hi, I'm developing a Blackberry application (JDE 4.6.1) and I need to import into my project some code packed in a .jar archive (let's call it YYY). The problem is that no .cod file is generated from that when I build my application (only the main application one is created),so the emulator show a message like:

error: YYY module not found

does anybody knows a way for forcing the .cod file creation in Eclipse? p.s. I'm supposed to build the .jar file as a library

thanks a lot