fhchiang,
9M is the country designator registration for all aircraft for Malaysia whether the aircraft is for commercial or private use.
Just like Australia, it is VH-### or New Zealand, it is ZK-### and so on..
I have a few friends that came from Australia with Australian CPL/IR and to give you an idea, they came with just a bare license so Malaysian DCA requires them to "again" sit for:
1. Two Air Law Papers
2. Performance 'A'
3. Loading
4. HPL
5. Six ATPL Papers if you are planning to join companies like Air Asia or MAS and so on....etc...
6. And also your Malaysian Cat 1 Medical
7. C.O.T. (Cerfiticate of Test) such as on a PA-34 with MFA to get a fully endorsed Malaysian CPL/IR.
Hope this helps and to give you an idea of what you are getting into. But of course, it's best and wise to check with the Malaysian DCA for proper procedures prior to setting up your plans.
SBox