How do I add combobox to system form matrix and load data into it.

I would like to add combobox as new field in all the marketing documents and load values into it.

We are working for button manufacturer.

Each button will have type,color, size, thickness.

There are about 100 types, 40 colors, 30 sizes, 10 thickness.

Above 10000 item codes will appear.

Selecting each item is very difficult through default options.

So, client wants to choose type, color,size, thickness so that item code should appear automatically.

Next row, all the type, color,size should repeat itself. If thickness is choosen item code should appear automatically.

Or if any change in one of these, change it so that item code should be formed automatically.

Working out formatted search looks to be very difficult for the client.

Using UDF with list values doesnot load data from database.

So, this thing should be possible through SDK.

I was trying to add combox to System form matrix. But, it is not happening.

I am not able to proceed.