Combining ntlm_auth and mac address verification in freeradius

Hi there. I've got the problem that I want to combine active directory authentication with mac address verification. So only user can log in which hardware is listed in a text file or similar. In the whole world wide web I didn't find a hint how to combine multiple authentication methods in serial. One possibility, but there I didn't find anything at all, seems to be using the perl module. Is it possible to run a perl script before ntlm_auth will take place ? Thanks for your answer. Greetings from Switzerland. Mike