Is the matched condition stored in a variable?

Is the matched condition in a recipe stored in some builtin  variable for later
use?
$MATCH will not work because it only stores right hand side of the regex!

For example: I have a recipe as below,

:0 c
* ^TO*\(_at_)domain*(_dot_)*
domain-stuff

I would like to store the matched string into a variable.
For some odd reason, the recipe:

:0
* ^TO(_dot_)+\(_at_)\/.*
{ DOMAIN=$MATCH }

stores the DOMAIN after alias expansion as opposed to the domain to which the 
mail
was ORIGINALly addressed. I guess the ORDER in the "^TO" macro ai'nt helping! My
ULTIMATE goal is to GRAB the ORIGINAL address to which the mail was sent into a
$VARIABLE.

Sreenivas.