Is there anyway to run 64-bit guest on a 32-bit Host?

I have 2 power edge 1950 with ESX3 but i wont let me install a "Windows 2003 enterprise 64-bit" OS

Is there anything I can do make this work. I just want to check a bit software works on 64-bit system. I also tried workstation6 and that complained too.

Is the only way to run 64-bit guest is to have 64-bit host?

Thanks