Same Page Printed But With Changing Sequential Number On It

I have a selected area which I print as labels.

I want to have a number on this label preferably counting back from the quantity of print.
So if I select 300 copies to print, the first label shows somewhere 300, the 2nd label 299, the third 298 and so on.

I use a button and macro for printing selected labels, so perhaps the reverse printing could be added there if only counting up is available.

Also to make it easier, a cell on the sheet can contain the number to count down from (this is preferred on thinking about it) So I could then print 20 labels from 300 to 280 say.