How to create a Plugin Installer

[nevetS]

Sorry that I wasn't more clear:

1) get input from user about 3 things:
carp install location
carp cache location
cache refresh time period
2) dynamically update the xml for the plugin based on these variables.
(this part I can do pretty easily with php code)
3) upload the plugin xml files automatically. (so the user doesn't have to do it in a separate step)
4) display additional configuration information and an installation success/error message.