I think the browser determines how the new window opens. You can have the button open a pop up with a template component that 'iframes' the URL you are trying to open.
It looks like you want to provide a way to lookup a zip code. You may want to build a zip code lookup in Skuid. You can connect to the API at this site to do look ups of City/State/Country that returns the zip-> http://www.zippopotam.us/ Then you could return the value back to your form.