Texturing random shape.

How could I apply a scaled, rotated texture to a random shape created with Drawline?
For example...

Graphics 640,480
DrawLine 10,10,400,10
DrawLine 400,10,400,200
DrawLine 400,200,300,200
DrawLine 300,200,350,150
DrawLine 350,150,10,10
Flip
WaitKey()

Thanks

By creating a Trianglefan out of this 5 points and calculate their UVs

Thanks Dreamora.
I'm struggling to convert gl type co-ords to 2D line co-ords. Is there a simple method?
I'll be keeping an eye on SoggyP's drawpoly query as well as it would be nice to do this without OGL stuff.