If you have your AC3D object textured .... export it as a .obj file
Open it in UVmapper (the classic version I believe is free :
http://uvmapper.com/index.html). You can play with the map, then export the modified map AND .obj file using modified map. Import your new mapped .obj file into AC3D.
There is a tutorial shows the remapping of a poser figure at the site.
If you don't have your object textured .... colour different areas of your object with different colours roughly how you want to apply texture. Load into UVMapper do a simple planar map then select parts by using *select by material* to rearrange and scale. Export new mapped .obj and the newly created map. See tutorial above mentioned above.
griff