LAMMPS Query:How to create a vacancy at a particular location in a simulation cell and add atoms into that vacancy at that particular location

Hello,

I have just started to work on LAMMPS and I have managed to create a vacancy in a simulation cell but unable to define the location of that vacancy. Can anyone help me?

Also I need this location as I am adding atoms into that particular vacancy location. Could anyone aid me in that too?

Thanks.

Bopanna