here is a routine that will take a string and convert it into a reg_binary format
code:
$label="string to convert"
for $loop = 1 to len($label) ; ******* parse the label and convert to hex string
$hexchar=dectohex(asc(substr("$label",$loop,1)))
$hexlabel=$hexlabel+$hexchar+"00"
next
while len($hexlabel) < 128 ; ******* Buffer the hex string to 128 characters
$hexlabel=$hexlabel+"00"
loop
