Check here...

http://soase.weebly.com/add-planets.html#GalaxyScenarioDef

Thanks mate ,

This is what I was after. As I am already using "Distant Stars" mod and all I simply want to do is add more custom planets to the custom planets already included with the DS mod. I am therefore basically looking to edit the DS "GalaxyScenarioDef.file" already in my GalaxyForge folder.

One question though re: your link. Where the author talks about PLANET ENTITY and uses the example of "planetswamp.entity" located in mod/gameinfo, this is a .BIN file. When I open .BIN files using wordpad++ all I get is a bunch of unrecognisable symbols. So how do I read .BIN files?

Great mate (the modding in MTWII is so much different to this, I guess adding planets is not as simple as I originally thought).

I managed to convert the BIN files into TXT using a GUI converter. The question then is once I am done using the files do I need to convert them back to .BIN? or will everything still work fine if I leave files in .TXT (this mainly pertaining to planet.entity files at this stage).

Thanks for all the help and advice. Finaly managed to import my x1 custom planet. All and all; troubleshooting included, the whole process took no less than about 8 hours to do and x1 Distant Stars mod reinstall. I am such a noob when it comes to this.