Accessing Tablerow Child Control By Type

I'm iterating through a collection of asp:tablerows to be able to get or set the text in a textbox that is nested in the third cell of the row; I'm doing this by type rather than by ID because the cell ID's in that column aren't totally consistent--thus I can't really call FindControl() to achieve this. I've resorted to casting the third control in the TableRow to a TableCell and then Casting the first control in that cell to a TextBox. Not quite correct, as I'm getting an index out of range exception thrown. The problem mainly lies in the Controls.Count() property of the third cell, which comes to zero. Not sure if there's a better way to access the textbox---should I resort to FindControl()?

foreach (TableRow row in tblProviders.Rows) {
string value = ((TextBox)((TableCell)row.Controls(2)).Controls(0)).Text;
...
}

My searches here only yielded use of FindControl(), so that may be the only way...