Here's some that I use in a couple places in Workflow, I'm sure it'll probably work in QF too.

These all assume the format is one of two options (the | symbol means OR):

1. City followed by comma, space, 2 letter state, space, and 5 digit zip.
2. City followed by comma, space, 2 letter state, space, and 10 digit zip (zip+4 with hyphen).

City:     (.*)\,\s\w{2}\s\d{5}|(.*)\,\s\w{2}\s\d{5}\-\d{4}

State:     .*\,\s(\w{2})\s\d{5}|.*\,\s(\w{2})\s\d{5}\-\d{4}

Zip (if you only ever want the 5 digit):     .*\,\s\w{2}\s(\d{5})|.*\,\s\w{2}\s(\d{5})\-\d{4}

Zip (either the 5 digit or the 10 digit):     .*\,\s\w{2}\s(\d{5})|.*\,\s\w{2}\s(\d{5}\-\d{4})

These all use the same structure, it is just the ( and ) symbols that indicate what part you want to retrieve.