Chemistification

Hi all, I would like to know if there is an add on available that gives you multiple undo's in microsoft project 2003. I find it annoying that it will only let you undo once. Please can you let me know if there is anything i can do to gain multiple undos. Hope this is in the right place on the forum. If not please let me know where i should put it and i will try and move it. Thanks in advance for your help. Many thanks, Chem