Is there any way to make an item that turns you into an elder air elemental and back to your origional form when ever you want? If there is could you tell me what I need to do?

You might want to take this question to the official boards. Though I am fairly certain that without hack packs, it is not possible...

This can be accomplished using the in-game command console.

1. Press the ` key to open the console
2. Type in DebugMode 1 and press Enter
3. Type in SetAppearance 053 and press Enter (053 is the number for elder air elemental)

That should do it. I think you can repeat the process replacing 053 with one of the following numbers to return to your normal self. I've never tried this part though so it might not work...

000 Dwarf
001 Elf
002 Gnome
003 Halfling
004 Half_Elf
005 Half_Orc
006 Human

There's a guide at gamefaqs.com called Playable Skin/Monster Guide that explains how all this is done:
http://www.gamefaqs.com/computer/doswin/game/27528.html