File Upload through GF in front-end to ACF in back-end

I created a simple form with a single purpose, to create a post and give the logged-in user in the front-end the possibility to upload a document through the file upload field. It's creating the post, but I can't figure out how to connect Gravity Form's file upload field to the Advanced Custom Fields file upload field in the back-end.

I've chosen a ''Custom Field'' for the form from the ''Post Fields'' and set the custom field name to ''Existing'' and chose ''file_upload'' which is the Advanced Custom Fields field name that I use in the back-end.

http://www.modassicmarketing.com/support/gravityforms/Screen%20Shot%202013-06-28%20at%209.15.58%20AM.png

This is how the front-end looks like if anyone cares to see:

http://modassicmarketing.com/support/gravityforms/Screen%20Shot%202013-06-28%20at%209.33.36%20AM.png

Submitting a document works flawless:

http://modassicmarketing.com/support/gravityforms/Screen%20Shot%202013-06-28%20at%209.35.00%20AM.png

Gravity Forms created the post through the document upload. But the file is not where it's supposed to be.. in the Advanced Custom Fields upload field:

http://modassicmarketing.com/support/gravityforms/Screen%20Shot%202013-06-28%20at%209.36.12%20AM.png

Does anyone know what I'm doing wrong?

Thank you very much.

We played around with this a bit and had no luck. Gravity Forms saves the items correctly when it is regular custom fields. When we used Advanced Custom Fields to create a new custom field, that field did not show as an option to which we could map our custom post field in the form. And if we typed the custom field name given to us by ACF into the custom post field as a new custom field (instead of the existing radio button), it was treated as a new custom field, not an ACF one.

I think you will need to talk to the creators of ACF to see how it should work. We did notice they have some Gravity Forms add-ons for it so they are familiar with our product.

Did that help in any way?

Thank you.