Drag and drop texture to specific VrayMtl slot?

I would love to see or get info where i can get a script, which allows you to put a texture with drag and drop method (from windows (from acdsee image explorer for example) to a specific vraymtl slot.
The drag and drop method in max works, but it works in a way where it always crates a standard material and place the selected texture to diffuse slot, i need the drag and drop method to maintain the vraymtl on the object and all textures in different slots and just puts (or replaces) texture in the vraymtl slot you want (diffuse, bump, specular etc.).
Could someone make it? Or does someone have it already? For example with some basic UI which allows you to switch between slots in which the drag and drop method will work?