Inventory setup?

I have been trying to get a inventory system set up to work with the stock TGE inventory and the Drag and Drop resource. What I'm looking for is when the player opens up the inventoryGui is displays slots for the mounts of the player and other slots for the players inventory "backpack". So lets say I just found a weapon and pick it up. It will display in my "backpack" then I can open the inventoryGui and drag it from the slot in the backpack and drop the weapon on my slot for my right hand "mount0" and now I can use that weapon.

Thanks,
Tek0