Adwords Question: How to track form submitted to external site?

[PocketSEO]

Is it possible to use Google Analytics to track a form (e-newsletter signup) that is submitted to an external site?

I want to track Adwords conversions:
* user clicks on Adwords in Google SERPs
* user visits Web site and signs up for email newsletter -- but the signup form submits to an external site

I thought about using an onclick event of the form submit button that would go to a virtual URL like /outgoing/newsletter-signup and then set up a goal for that URL -- but it didn't work in my tests. Also, I'm not sure that it would track newsletter signups that originated from Adwords.

Any ideas?

[GuyFromChicago]

Add a page in between the submit to external site that only includes the conversion code. Just show them the blank page for a second or two then redirect to complete the submission.

[PocketSEO]

That's a good idea, thanks.

[GuyFromChicago]

No problem. Just makes sure to leave a second or two before the redirect. If the JS can't load the conversion won't be captured.