Which modelling program are you using? Assuming it's Gmax I recommend Chris File's MiddleMan. http://thegreatptmd.tripod.com/
This will give you the option to export CFS2 compatible models direct. I find these also work fine in FS2002.

There's a tute posted in the SimV design section explaining how to hex edit an FS2002 MDL to work in CFS2. I haven't tried it as it's time-consuming & still in the beta stage. The converted aircraft should be OK in Free Flight but might not work properly in QC or missions.