I believe more elegant solution is to use powershell. It's certainly better than using Cygwin on a Windows machine - for one thing it's built-in.
In Bash we write:
dig axfr my.domain | grep "80"
The equivalent in Powershell would be:
nslookup -ls my.domain | where {$_ -match "80"}
Or even better to use regex to make sure only lines ending with 80
are going to be matched:
nslookup -ls my.domain | where {$_ -match "(80)$"}
Additionally if you are interested in domain zone transfers, you might find this answer useful (and here's a GitHub project).