PCBs can be partially converted by C@MC@D, but you have to extract the @llegro file using a utility included with @llegro. Even then, split planes, polygons, etc won't be carried over into the Pr0tel board.
The short answer is that you can't make the conversion satisfactorily. I spent a lot of time looking for a good solution - I ended up redoing the board from scratch in Pr0tel.
I know that C0ncept is the schematic tool - I was trying to give him a complete answer.
As for converting to 0rcad DSN and then to Pr0tel - try it yourself, and you will find that many of the components don't show up, some of the busses will not translate, etc. I have many years of experience, and I have yet to be able to get a decent translation from Allegr0/C0ncept to Pr0tel.