Newbie question about formail

I'm trying to figure out the combination of switches needed in formail to 
change a Subject: on an incoming mail to a different subject during an 
auto-reply. 

Here's a snippet of the script that I've borrowed from someone else's 
post.  Do I need to drop or modify the SUBJECT line?  I'm new at this!


{
   FROM=`formail -rx To:`
   SUBJECT=`formail -xSubject:`

(remainder of script goes here...)

}


Greg
batchman(_at_)dsp(_dot_)net