TCPRULES howto use variables?

Does anyone know howto set a variable with another variable in the tcprules CDB ?

I'm trying to achive 2 things, one is RBL related the other more general.
First det RBL spam thingy:

=.spamdomain.net:allow,RBLSMTPD="-Die spammer, DIE!"
=.somebadspammers.net:allow,RBLSMTPD="-Due to much spam from your domain I have banned $TCPREMOTEIP"
=:allow,RBLSMTP="You do not have a valid RDNS entry"
:allow


I'm also using tcprules with other programs, and need variables here too:
10.0.0.1:allow,USER="Peter",PATH="$PATH:/home/$USER/bin"
10.0.0.2:allow,USER="Grace",PATH="$PATH:/home/$USER/bin"
10.0.0.3:allow,USER="Will",PATH="$PATH:/home/$USER/bin"
10.0.1.:allow,GROUP="Accounting",PATH="$PATH:/home/groups/$GROUP/bin"
:deny

It is possible to avoid use of $USER and $GROUP, but the $PATH
is worse since it will need to be changed in the future.


Regards André Paulsberg