I agree with RussB.
I have done this a few times between different PLC platforms, and I was sorry every time.
A lot depends on how clean the original program is and how good the documentation.
Sometimes you can have a program written by a 'committee' which can be a lot of fun to decipher.
Converting the code is only phase 1, the interesting bit is commissioning.
I suggest you learn the process and do your own program for the new PLC. You will know
how it works and your commissioning time will be less.