Shipping question

Is there a way to make it so that when I ship something, instead of it going from pending to complete, to add a step in the middle called xxxxx. Basically what i need is that I have it pending, and shipped is literally when it went to site, and then 'complete' when it will take it out of my inventory.

The problem I'm having is that with simply accounting if i remove my tracmor inventory it causes issues. So I am trying to get it so that the last shipping step will be done by accounting when they make the invoice which will remove it from that inventory.

If so please let me know.