Populate a textbox inside a datagrid on loadform

[anna]

I have a grid with some columns that are BOUND columns. I have three
more columns that are TEMPLATE columns with textboxes inside. i need
to populate one of the textboxes with information based on a
parameter... the code below works on a textbox outside of the grid.
how would you use the logic to populate txtDiscCov inside a grid.

If Not IsPostBack Then
sqlPropLU.Parameters("@PropID").Value = lblEntryType.Text
SqlRating.Open()
Dim dreader As SqlClient.SqlDataReader
dreader =
sqlPropLU.ExecuteReader(CommandBehavior.SingleRow)
If dreader.Read() Then
txtDiscCov.Text = dreader(1)
End If
dreader.Close()
SqlRating.Close()
End If
tried the --- Dim txtDiscCOv As TextBox =
CType(grdNotes.Cells(0).Controls(1), TextBox)-- have the syntax wrong.
Any help would be gratefully appreciated
(0).Controls(1), TextBox)-- have the syntax wrong.
any help would be greatfully appreciated