VS 2008 - Gridview Control - User Edit Only One Column

I have a gridview control on .aspx page. Situation is, the columns in the gridview control are not databound. I query the database and load the gridview control using the following code.

GridViewstockcalc.Visible = true;
GridViewstockcalc.DataSource = dataSetstockcap.Tables[0];
GridViewstockcalc.DataBind();

The gridview control shows about 13 columns from the database. But we want the user to be able to edit only one column. Rest of the 12 columsn should be read only. When the clicks one Edit button button, as usual the Update and Cancel buttons should come up. It is not happening. Only the _Rowediting event is getting trigged. Following is the code from my .aspx page. I don't know anything about template columns and not sure if I have to use that concept in my situation.

<asp:GridView ID="GridViewstockcalc" runat="server"
HeaderStyle-BackColor="#444444"
HeaderStyle-ForeColor="White"
onrowcommand="GridViewstockcalc_RowCommand" Height="150px"
Font-Size="Small" onrowediting="GridViewstockcalc_RowEditing"
onrowupdating="GridViewstockcalc_RowUpdating">
<Columns>
<asp:CommandField ShowEditButton="true" ShowCancelButton="true" />
<asp:TemplateField HeaderText="ticker">
<ItemTemplate>
<%# Eval("ticker")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox runat="server" ID="txtticker" Text='<%# Eval("ticker")%>' />
</EditItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="fhlb_ID" HeaderText="ticker" ReadOnly="true" />
</Columns>