You can use on the menu to re-order or re-number the levels in a game or to move a level from one game to another. is a two-part operation. You must first load a level by selecting it for editing or play, then when you use , the Level Selection Dialog box appears and you can select the new level number and game (as required).
Moves leave no gaps in the sequence of level numbers in a game. For example, if you move level 10 of game A to level 3 of game B, levels 11 and above in game A are re-numbered down by one (to close the gap) and levels 3 and above in game B are re-numbered up by one (to make room for the newcomer).