[Exim] radius quetsion

Hello,
I would like to ask you, if there is in exim any possiblity to get path to user directory via radius protocol.
Something like avpair or so?
I have few datatables, uniqe db user and database name for each virtal domain, and i want to take path to user maildir via radius server.
Or meybe exim can take as 'directory =' directive output of external program ?

Best Regards

Jan Kowalski