You need to convert the obj file to 3ds (with meshlab or wings 3D). Then you can open the parts in pcreator. You have to load a 3ds file in it, then you need to apply the texture of it (you have to save it as bmp) after this open View --> UV Coords --> check flip y and after that you can save the whole thing as a p file. Don't forget to convert the bmp file to a tex file (with image2tex)
As a warning: don't release any ripped model from another game (or models without the permission of the original author*) here. Most times these models are only meant for personal studies and not for public use in a different manner.
*I think we are here on Qhimm quite cool, so if you alter a model from here and say it is tweak you did of the model XY from the author AB and release it, it won't be that bad. But don't touch models were the author say any alteration isn't allowed. Ask before and tell him what you are intend to do maybe you get a special permission.