seac: System conditions, actions and expressions are built-in C2.
A custom plugin developper could do nothing about it.
You can already executes events after a loop :
<img src="http://dl.dropbox.com/u/36472942/construct/forumhelp/AfterLoop.JPG" border="0">
No need for extra conditions, just remember event sheets gets executed from top to bottom.
In my screenshot (strictly an example, this code as it is is pretty useless):
When 0 = 0
Runs a loop "tt" from 1 to 10
Then will automaticly execute the actions from event 3 after the loop, as the blank subevent here, is at the same level as the loop.
Strange thing is that you setted it in your screenshot.