Weapon model holding

[nolimes]

Hello. I am working with my fan project of Kal Online placed in Web App (clicker game like Shakes and Fidget etc.). And i want to put inside of it visualisation of player character like in-game. So i`ve created a tool using JS libraries etc. and i successfully imported all neccesery stuff to shows models in browser (models, textures, even bones for char pose) but i can`t find how (some file? some script inside game folder) to connect weapon model with character model. Just look at those screenshots:

Maybe someone could give me a tip?