HELP: Disable stacked item in first slot of backpack

[diviee3]

Hey guys,

I saw on a server a fix that would prevent duping for good. They made it impossible to put a stacked item into your first slot of the backpack. It just says "That item dont go in that slot".
Can someone help me with that? I dont know how they did i think its C++. I really have no clue how though... but if anyone knows how to do such a thing can they share it please.

Thanks in advance, it would really help out my server

(I'm running an Arcemu 2.4.3 server, the server i saw this trick on is also 2.4.3)

[diviee3]

Comon people no one knows such a thing? Its gotta be something in items script for c++ that controls whether an item can go in a specific slot... just i lack the skills to modify it. please help