input products from a form

I have put together a somewhat complex order form for custom built items, where customers can make there selections (dimensions, color, add. options, etc.... even an upload space to send pictures of the area they wish to install it) and ultimately come up with a price for their product. I want to be able to have some of the forms data, especially the price of the item, exported to a shopping cart page where customers can then either go back and create another product to add or check out. I could do the entire process on a form... payment and all, but have no easy way of retaining customer data, being able to run coupons and offering re-salers a discount plan for wholesale pricing.

Are there any existing ways to send customized products from an external source to the cart, or is this something that may have to be done from scratch?

I will also be offering prebuilt items in my store using the standard system. I really want to integrate everything into one place and allow customers who are purchasing a custom item to also have the ability to purchase other standard items as well.

I have searched and searched for a solution for days without much luck

Any help or ideas are greatly appreciated.

Thanks, Jay

If you are going to use Zen Cart then you should use the atributes system for your "buildable" product. The program is not set up to accept input from outside the program.

The issue that I am having with using the attributes system is that I need for a calculation to be preformed using a customer entered width, height and depth. This has to be multiplied by a figure given from the attributes of the product the customer chooses from misc. drop down lists. From what I can tell, this seems a little more complex that the zencart attributes is set up to handle... I may be wrong though! I am up to about 100 form fields on the order form I've created, most dependent on selections made from other fields....and they are still growing. The form works perfectly for what I wanted it to do.... it's just the overall processing of the form I am having trouble finding a way to integrate to my site. Right now, I can have each item sent to a paypal checkout individually, but for customers who want more than one item, it's just not efficient.

Is there a way to maybe have the amount tallied from my form be entered as an attribute in a general item set to $0 in zencart, as well as some of the information in the form be carried as an attribute without a value set. That way the item is already in zencart, but the information effecting price is being imported from the form. ..........just an idea! I have not done too much with the product attributes in zencart, except for some experimenting..... there are probably features I have no idea about!