Programatically set shortcode argument

I am using gravity forms to add and edit a product post from the frontend.

The shortcode parameter to edit a post is:
[gravityform id=”1″ update=”451″]

Where 451 is the product post id.

Currently the admin needs to find the id and manually insert it as the argument.

I need a front end plugin that lists product posted by the logged in user who is in the Author role.

The user should be able to select a product on the list that they would like to edit.
Then the shortcode should be reset to allow the user to update the product post.

ie.
[gravityform id=”1″ update=”465″] where 465 is the id of the selected post.

Any reference would be appreciated.
Thanks,

Dovberman