You’d be pretty lucky to just walk into any art or design related course without any art experience or portfolio…Consider taking a 1 year portfolio course or getting private advice/tuition. Skill with a 3D modelling tool doesn’t count for much with admissions staff in most colleges, they’re quite traditionalist.
Also, do you intend to start this September? I think its too late…application deadlines have passed. If its Sep 2007, watch out for those U.K. deadlines, the good courses often set them much earlier than normal, like around the end of this year.