Splitting username(_at_)host(_dot_)

Hi,

I've got a recipe which looks like:

:0
* RCPT ?? ^^\/.*@
        { USER = $MATCH }

The RCPT variable is set from the arguments and basically I'm trying to
pull out the username... The problem is the fact that it matches
"username@" as opposed to "username".

I've tried ^^\/.*?@ to perhaps turn off greedy mode, but that doesn't help
either.. 

Any ideas would be greatly appreciated! :)

//umar.