I got 3 programs that can help you out. One of them is GCT Fusionizer, which can make a bigger gct from 2 smaller ones. It would be a matter of having the stage expansion code in a separate gct, and fusing it into the other one afterwards. Another program would be GCT Analyzer, one can add codes in text, or just from a gct, just like GCT Fusionizer. The third program is the Stage Expansion Roster Tool, that program enables the stage expansion in the gct you open with it. It allows you to customize the order of the stages, and the icons they use.

Oh my lord, thank you so much!
I've been trying to use different programs and I keep deleting my GCT somehow, Thanks a lot!

Hey, I actually made a thread about this but I already have the Dark flaming red CSS+SSS, so I have tons of codes from the get go, So after I put in my codes, I tried exporting it to GCT (I tried using both Geckocodes and Code Manager) but since i have 200+ codes enabled from the screen codes, I don't have any room.
Is there any way to bypass this?
oh, I didn't specify what I'm trying to get, I'm trying to install the Stage Roster Expansion.