give USB webcam a permanent ID

I have build an application that shows 6 webcams at the same time. So I simply used the IDs which are automatically (random?) given each cam to select each one and position it on the screen.
Now I want to make this system more reliable. If a cam breaks (because of falling down) then it should be replaced by a new one. THE PROBLEM: if I unplug the broken cam and plug the new one, the new one will have an ID that might be somewhere in between the others. This means, that all IDs after this new camera are switched (+1).
Of course I could solve this with coding, but I wonder if there is any possibility to give each attached USB camera a fix idea, that will always be the same?
Maybe this is not a OF issue, but should be assigned in Windows? (in my case Windows7)
A solution would also the switch Hardware IDs in Windows, but in the device manager i did not find any solution.
If anyone has any idea or hint, this would be great. Thank you very much.