You're welcome.
You can try adding just the domain, but I don't know if that will work.
I don't know how you might get around any total input restriction.
If that doesn't work, you can add multiple IPs by using a comma as a separator, e.g. IP1,IP2,IP3,IP4, etc.
I also don't know if there is a way of inputting a range of IPs, e.g. 123.0.0.1-123.0.0.26, etc. assuming that there is a range of IPs which it can be applied.
Unfortunately I can't be a great deal of help as I'm working from memory and old images as I no longer use avast 4.8, but avast 5.0.507 and I would advise updating to avast 5.0 (not that it is any easier to do what you are attempting).
That's me for the night, 4am here.