Start Programs on Plugin and Eject

(BTW, you happen to know how to obtain the name of all executables
within every subfolder of a given folder??? I'm trying to figure out the
algorithm to write an app manager for the menu ;)).

What language? The basic idea is to start a search in your top directory for all files and folders (*.*). If a found item is a folder (do an attribute check) then you recurse into that folder doing the same thing, search for all (*.*). If the item is a file, check for the EXE extension and add it to your list. It'll end up being a small looking loop, but you call the function from within itself (recurse).

Now, in most languages this is fine because you can declare variables in a local scope (when recursing you won't overwrite your previous variables where you will store the search handles). NSIS doesn't make this distinction I don't think, so you might have trouble if that's your language.

EDIT - you're going to have issues in NSIS. From the manual -

4.2.1.1 Var
[/GLOBAL] var_name
Declare a user variable. Allowed characters for variables names: [a-z][A-Z][0-9] and '_'. All defined variables are global, even if defined in a section or a function.

It works for me...
Don't right-click and save target as because it goes to a webpage first.