Hmm. Not tested, but (with novarsinstrings) maybe...
Code:
     $i=''
     $objOU = GetObject($LDAP)
     $aFilter[0] = $Filter
     $objOU.Filter = $aFilter
     $result=Execute('for each $item in $objOU
         if $item.class = $Filter
             $i = $LDAP
	     if $i="some value" Exit 1 EndIf
             endif
         next
         Exit 0')


As a benefit, $result will be true (1) if the result is found.