Vlk
2
URL blocking in WebShield is quite different. First, it’s for HTTP (web sites) only. Next, it looks quite different when you try to access a blocked site - try it yourself.
About the possibilty to import the list - here was some discussion about this http://forum.avast.com/index.php?topic=10803.0
The answer is “sorry, not at this moment”, a much more complete URL management package may be actually part of one of our upcoming products… 
Cheers
Vlk