regular expression blacklist on T28 on 2.72.0.30

[lynn@gigglefiber.com]

Metaswitch 2510 to a t28 on firmware 2.72.0.30 with a public IP connected directly to the lan port of the modem. No router to place rules or NAT, only the blacklist to assist. Also these calls are not hitting the switch. The are probably scanners simply hitting the public ip looking for a hole. One night i removed the password and the next day it was forward to another place, I had ld blocked in the switch so no harm but they are (insert expletive ) persistant. I would like to limit accepting call from only 10 digit numbers but it seems that i would need to use some type of regular expression and it looks like this is not supported. any help, ideas, fixes or even denigrating comments are welcomed.

Thanks in advance!