Putting Molecules in specific coordinate in the simulation box

Right now, I am copying each molecule and putting it inside the simulation box and use the movement tool to place it close to my substrate. Now, the issue is, I have to do it for a whole lot of molecules. So I am looking for a script that copies a molcule and places it in the simulation box above a substrate on a specific coordinate. Does anyone have a script that does something similar or any ideas? I appreciate it. Thanks.