SaintDragon, I think I know what you are doing, and I don't think it's goinf to work. The PC and PSX executables are WAAAY different.
For example many lookup tables and internal scripts like the tutorial and menu subsystems are in the PC executable, and are in files in the PSX version. Not only this, the PSX executable is hard-coded to data locations on the disc. The PSX does not open any files by filename, only by sector location. The system is very corruptable and resistant to mods. Unless you plan on re-authoring the disk, your mod attempts are going to end in a lot of frustration.
When FF7 was compiled for the PSX, lookup tabes were created, filenames were stripped, a disk was authored at the same time. It's actully really intresting, and also why FF8 has *NO* filenames in it whatsoever, just a big bin block.
That being said, good luck with what you are trying.