Stripping the calling station id

[Kefi Ammar .]

Hello,

Could someone help me to strip the calling station id recieved in the
request to use it later for the checkval module.

I am applying the mac authentication using checkval but the problem is that
I am recieving a long calling station id containing the mac address.

this is an exemple of the calling station id recieved : lag-50:1201.0#BNG
Kasbah###pppoe 94:a7:b7:3e:93:5b#

its always in this format and I only want to extract the mac address from
it. I dont know if it can be achieved using unlang or anything else.