There is no equivalent of ExitFor or ExitDo. It's been something that has been requested over and over. In all honesty, the coder should code better to handle that kind of thing. One of the ways I've gotten around it is to add a $found variable. And as part of the loop check to see if $found is set or not.

(these are untested)
 Code:
$i="abcdefghigklmnopqrstuvwxyz"
while $i and $found=0
  $j=left($i,1)
  $i=right($i,-1)
  if $j = "n"
    $found=1
  endif
loop


Using your example:
 Code:
Do
	$LoopCount = $LoopCount + 1
	MessageBox($LoopCount,"")
	;If $LoopCount = 5
	;	Exit Do
	;EndIf
Until $LoopCount=5
MessageBox("Final Loop Count: " + $LoopCount,"")


0's and 1s...
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=81941#Post81941

All the FAQs...
http://www.kixtart.org/forums/ubbthreads.php?ubb=postlist&Board=5&page=1

The console is appearing because you have output. Cleaning up the 1's and 0's is a step in the right direction.