Ok this should work on the version you are running. I'll explain $VlanMac
\b says there should be a word boundry ie. no letters or numbers before
\s says it needs to be immediatly followed by a space
[\w.]+ matches the mac address as any number of word chr's or a period.
Trigger-Variables:
$VLANinterface string
$VlanMac /\b28\s[\w.]+/
Trigger-Template:
[[$VlanMac]] DYNAMIC [[$VLANinterface]]
In later versions the VlanMac isn't needed and you can use
Trigger-Template:
\b28 [\w.]+ DYNAMIC [[$VLANinterface]]
Try that first and see if it works on your version.
Hope this helps
Bob @ Eqalis www.eqalis.com