How can I chenge the Key of a collection...?

[npolo]

If I populate a collection with: A,key=1 B,key=2 C,key=3
and D,key=4 and then if I remove item B which is key=2, how can I re-arrange the keys to be A,key=1 C,key=2 and
D,key=3 ....????

[phinds]

no can do --- you'd have to remove all elements and then reinsert them with the keys you want