I am presuming that you have the program on disk (or file) and it is in MEDOC.
The answer is yes it can be changed to GPP-WIN format
When you install GPP-WIN (or GX developer) You are given the option of
-do you want to import files from melsec medoc-
If you do not install this feature, then you cannot (re-install gpp with this feature)
If you have this enabled then go to
project/import file/import from melsec medoc
Find the folder that the medoc program is in and open it.
Then use 'save as' , give it a name and it will be saved in gpp-win format.