Is it possible to install Craft on a cPanel temp user URL?
http://buildwithcraft.com/docs/multi-environment-configs

'example.com' =&gt; array(...


'should' work with an address like:

'123.45.67.89/%7eusername' =&gt; array(...


You might also try:

'123.45.67.89/~username' =&gt; array(...


Although using a proper domain name as in my comment above would be better.

Good luck. :)