Need Help Fast

I spent all this time modelling and texturing a level for a game im making

and im not using the game engine from blender

my friend wrote his own in darkbasic

SO the important part:
I have:
a model
and some .png’s that were made by UV unwrapping the model, then drawing on that in GIMP

I need:
the model as a .x
so that i can put it in his engine and it will be textured

this is for something due this friday