Show multiple related table columns in sharepoint select box (bug database)

I'm doing some basic bug tracking using Sharepoint, and we have three lists setup.

1. Product list (includes product name and description)

2. Production version list (shows the versions of each product we have). Links to the products table via field "Product"

3. Bug list (linked to the product version list via field "Product Version").

When a user enters a bug, I'd like them to have a drop down menu from which they can select the affected product and version. (That bug will also be automatically associated with the correct product because the product version list is linked to the product list).

So far, I've created a linked column in the bug list that references the version number. As yo开发者_Go百科u'd expect, when the user goes to select the product version number, they see a list of all the version numbers of all our product versions, without knowing which product the version corresponds to:

1.0.2

1.0.3

2.0.5

2.4.122

etc.

I'd like them instead to see:

Product A - 1.0.2

Product A - 1.0.3

Product B - 2.0.5

Product B - 2.4.122

I think that the route to doing this is to create a custom form, and when I'm configuring the control for the product version, I should be able to use XPath to configure how the display value reads.

I'm presently stumped as to how to create a custom form in Sharepoint Designer 2007 (the software always attempts to create me an automatic form based on the list's data types).

Any pointers, or suggestions of different approaches entirely would be greatly appreciated.

I would suggest to create a custom field type. you can take reference from following article how to create a new field type http://filteredlookup.codeplex.com/