Rad, it can be wimmied, here's one that clears the application eventlog, tested on xp:
break on
$query = "select * from win32_nteventlogfile where logfilename='application'"
$eventlog = getobject("winmgmts:").execquery("$query")
for each $entry in $eventlog
$= $entry.cleareventlog
next
exit 1
-Shawn
