If you mean using script developed for that game then no.
The only way to make an already developed rpg into an mmo would be to mod the code of the game itself so that it could connect to a server and properly send data back and forth. Not to mention, one would have to develop a creature server to maintain constant location of all enemies. For example, Rockstar Games origanally had planned to tak on a multiplay version of GTA3 with the single player; however, since the game was designed for SP, it had serious multiply problems, one such being that it was impossible for all game to properly share the exact location of ai cars. What one client saw, in terms of AI, was never the same to other clients.
Back to subject. It isn't imppossible to tern an sp rpg into an mmorpg, but would require and extensive knowledge of coding and the coding of the game itself.
