when you say pass, do you mean as the form is filled out it instantly makes the data available in the web application? If this is what your looking for, I think i have a website that shows you how to pull information from an infopath form using fields that are not promoted.
Infopath is essentially xml, so i am sure there are some easy ways to get the information.
If you need someone to submit the form and then have that data available to the web app, you can promote the fields and then use sharepoint web services, or even better the form submit to a database via web service and stored procedures and then your web app can communicate with the database.