Looking for network traffic from a list of domain names in firewall traffic that only has IP addresses.

I have a csv file with domain names. I need to search my firewall traffic to see if any traffic matches to/from any of these domains. The firewall logs only contain IP addresses, so I have to convert the domain names to IP addresses before searching for matches against the logs. I was hoping I could do this with the built-in "dnslookup" function. However, I am not having any luck getting this to work. I would appreciate any help! Thanks, Jon