I just read thru my original post and realized I didnt completely explain what I want to do;
I want to install the rocketlauncher into a separate folder
Yes you can do this, and ill suggest to create and addondomain to your second installation folder or you can just create a new folder on your server unzip the RT on the new folder and start with the new installation but be careful witn your databases tables. Don;t use the same as your other site if you do so you will overwrite the database for your working site
I can get that to work then I'll erase my orignal joomla folder.
It depends how your perform the installation to avoid any issues with your working installation and if this is for testing purposes only i'll suggest to create a new database for the new joomla installation or you can use only a differente table prefix.
This is the answer you need?
And addondomain is something like this.
Suppose your site is --->
www.mysite.com
and addondomain is --->
www.addon.mysite.com