Hi, Boris
As Arno said, there is an old tool called exactly that, Mdl-to-Bgl. Because there is no alternative, I have used it very, very often to place FS98 aircraft as static planes around airports. It works, but it needs some tweaking, as most of the apis that it generates come out with code that SCASM doesn't like. After a little while, we get used to it and go straight to the problem even before trying to compile with it.
Shadow is also missing, so you have to add the line ShaddowCall to the api before using.
Many times the planes come out nose or tail into the ground, as well as with the wheels too far above or below the surface. You will have to correct that, as well.
Most of the textures are in that format xxxxx.0af, 1af, etc. If you want to change the textures, such as changing a Congo registration for a Burkina Faso one, it becomes a bit of labour.
Fortunately, the FS98 aeroplanes are, for the most part, simpler than more recent versions of FS and are not extremely heavy on the Frame Rate. Your system will feel it, though.
I have quite a few aircraft already done. If you want them, send me an email at
fernmarques@yahoo.com and I will send you what I have, from Piper Cubs to MD11 USAF tankers, going through Tigermoths, F16, and a few others.
Fern