Initial buffer size at start of simulation

I`m making a simulation but at the start of the simulation the Stack is always empty.

Is there a way to make the floor stack start already with products in it?

I have tried to connect a feeder to it but that did not seem to work.

For now i have fixed this with a separate flow group, with a feeder that produces X lots in fast interval. If you have a different suggestion please let me know.