okay so it goes like this /Private/wii/app/RSBE/pf/fighter/lucas/ and inside are the pcs and pac files
Strange, that location is the right one..
Perhaps your GCT file is glitching, try making a new GCT file with the replacement code in it. Check if Gecko says it finds the code file or not. And check the Gecko settings to see if the codes are enabled or not.
Also, make sure the files are named correctly like:
textures/vertex: fitlucas##.pac/pcs (replacing the ## with 00, 01 and such)
PSA/moveset: fitlucas.pac
Motion file: .fitlucasmotionetc.pac