Hi,
Let me try to understand in own words.
1. You are building a Custom Contact Form by the help of a Custom Post Type – Which is fine. It will be able to accept the information and save into wp_posts and wp_postmeta tables. You need to tell WordPress what will go into wp_postmeta table.
2. You have probably already created the meta boxes. If yes, you will be able to show and edit them in admin as well. From user end, you just need to use a Form. Use save_posts_your_post_type() to save basic post type fields in wp_posts table like title, excerpt etc and rest of the fields to wp_postmeta table using upate_post_meta($post_id , 'meta_field_name', $meta_value);. The function update_post_meta first checks whether any the meta exists for the $post_id. If not it calls add_post_meta automatically.
3. In admin edit (your post type) you need to call the metaboxes to display the controls with their values prepopulated.
I am not very sure though if I could address exactly what you actually want to accomplish!
Hi Subrata
Thanks for the informative reply. I think my main concern was whether saving contact form data as a post rather than to a custom table was the right thing to do. It seems like a good way to manage contact enquiries but would rather do it the correct way.
Many thanks
Steve