Get a JAA PPL, then fly microlights on it. When you have > 250 hours and IF you wanted to get a JAA CPL, here is what you do.
You go to America and get an FAA PPL based on your JAA one. The FAA recognise your microlight hours as proper hours, and once you meet the requirements of CPL, you take the CPL test. You get this, and then you convert it to a JAA CPL via a 10 hour course or something....(+ exams etc..)
In theory this should work....shouldn't it.....?