Contact Form 7 – Redirect to different URL and pass variables

Hi, I know how to redirect to a new page after submission, but I need in this 2 form fields in contact form 7 to collect:

1. post code (zip code)
2. Consignment number

and then when the user hits submit, is transferred to the web page on a different URL: apc-overnight[dot]com/receiving-a-parcel/tracking/ and to pass the variables across from the contact form fields on my site to the two fields on this new site.

I have successfully done this in the past on different sites, but am missing something obvious I’m sure.

Any ideas? Thanks