here ya go.

this should give you an array called $userlist, this array will be a list of all the users who are in your abc* groups with no duplicates.

code:
break on

$domain = getobject("WinNT://@ldomain")

Dim $userlist[5]
$i = 0

$domain.filter = "group",""

for each $group in $domain
	if substr($group.name,1,3) = "abc"
		for each $user in $group.members
			if $user.class = "user"
				for each $name in $userlist
					if $name = $user.name
						$flag = 1
					endif
				next
				if $flag <> 1
					$userlist[$i] = $user.name
					$i = $i + 1
					if ubound($userlist) = $i-1
						redim preserve $userlist[ubound($userlist) + 5]
					endif
				else
					$flag = 0
				endif
			endif
		next
	endif
next

redim preserve $userlist[$i-1]

for each $name in $userlist
	? $name
next