Custom projection mapping

[coarse smelt]

Is there a way to apply a custom projection matrix to a particular mesh (or its texture) so that it looks proper to a perspective camera? I'm building a 2.5 D game that has the background perpendicular to the floor. The background is fine but the floor's texture gets squished.

Any help would be appreciated,
Regards

[long marsh]

i haven't heard of someone wanting to apply a projection matrix to a texture before...i've only heard of it as a vertex transformation step to get your camera presentation working