Asp.net - Iteratively Reference Controls By Name Pattern (.NET)?

Is there a way to iteratively reference an ASP.NET control based on it's name pattern? Perhaps by a "pointer" or something?What I have are a large set of comboboxes (each with an associated DropDownList and TextBox control). The DropDownList always has an item selected by default, but the use may wish to submit a NULL value. I come up with the following code to handle three cases: NULL, Existing Item, New Item.

'TextBoxControl & DropDownListControl should iteratively reference their
' respective TextBox & DropDownList controls by the actual control name

[code]....

The problem is, with so many comboboxes, I could easily end up with hundreds of lines of code. I wish to handle this in a more dynamic way, but I do not know if it is possible to reference controls in this way. Say I wanted to reference all the TextBox Controls and DropDownList Controls, respectively.

I can do string formatting with a given naming pattern to generate a name ID for any of the controls because they are all named with the same pattern. For example by attaching a specific suffix, say "_tb" for TextBox Controls and "_ddl" for DropDownList Controls:

Left(item.SelectedItem.ToString, item.SelectedItem.ToString.Length - 3) + "_tb"

Can this sort of thing be done in VB? Ultimately, my goal is to take the value entered/selected by the user, if any, and send it to a stored procedure on SQL Server for insertion into the database.