Boss spawn question / request

Hey guys, I need help with this Idea which I brought directly from the current Panadria expansion:

I want a boss to spawn in Bgs (WSG, AB, EOTS, etc) at an specific location inside there each time a new bg starts, but with only a small chance to actually spawn there (let’s say 5%) my guess is that this is possible. Can this be done solely thru db? or does this need c++?

If anyone could please help me with this script would be very much appreciated as I know little to nothing about c++

I do know how to handle the db though, so if it can be done thru db just tell me which tables to handle, I’ll figure out the rest I guess…

thanks /emoticons/default_wink.png