I have the original Steam version installed in my pc. I just want to know if exists any way to install the Nasomi in FFXI original and play the game, with the Steam Overlay and etc.
OBS: I DON'T WANT TO ADD THE GAME AS NON STEAM GAME IN THE LIBRARY.

You probably could with overwriting enough of the files to make it appear as a legit copy and not have Steam flag it... but why do you want to do this? Seems kind of pointless. Do you have an actual purpose for this? Are you allowed to have Steam installed somewhere or something but Nasomi?

that's just to take screenshots and use the steam overlay to navegate in the internet during the game... can you help me? i tried to paste the ashita files from Ashita folder in FINAL FANTASY XI folder, and then, i tried to rename the Ashita to polboot but it's doesn't works and... i tried too rename the boot file from ffxi-bootmod folder and doesn't works too...