Cool.
If you're using Badspot's BLB converter, it doesn't support textured faces.
You could do it by manually editing the BLB file though. You just have to find the right face and change the TEX:SIDE to TEX:TOP, TEX:BOTTOMEDGE, TEX:BOTTOMLOOP, TEX:RAMP, or TEX:PRINT. But then you'll probably also need to manually modify the UV COORDS.