uninstall from "string"

The uninstall section begins from

ReadRegStr $R0 HKLM "Software\AlykelSoft\IndicatorBoards\registration" ""

...

and all uninstalling process going well.
But confuse this string!
I think that is my default inst folder, how can I change it that it would be $R0?

Sorry, it's a path to uninstaller.
It's time to go sleep! ;-)