No, and it sounds suspiciously like a scam.
The license file for avast! 5 Internet Security is only ever called 'License.avastlic'
If you open the file with notepad (NB! Make a copy of the file first in case you accidentally edit it), you should see a section like this:
# Name of product: avast! Internet Security
#
Feature=AV_AIS
#
# License creation date: Jan xx, 2010
#
Issued=xxxxxxxxxx
#
# License expiry date: <never expires>
#
ValidThru=0
#
# Update license expiry date: Jan xx, 2011
#
UpdateValidThru=xxxxxxxxxx
#
# Number of licensed items
#
LicenseCount=3
If I remember correctly 'license.dat' is the license format for avast! 4.8 WHS.