I have added a control in the headertemplate of a
datagrid.  it's a dropdownlist control.  What I want to
be able to do is populate that control based on some
data.  My problem is that I can't access the control.  

I tried:  
DataGrid1.FindControl("frmpriority")
and
(DropDownList)DataGrid1.FindControl("frmpriority")
and
frmpriority (as if it were just a normal control outside
of the datagrid)

but those don't work, it simply cannot find the control.
               
How can I access the field:

code snippet:
    <asp:templatecolumn>
    <headertemplate>
          Priority<br>
<asp:dropdownlist runat="server"
id="frmpriority"></asp:dropdownlist>           
        </headertemplate>
    <itemtemplate>
        Content                   
    </itemtemplate>               
    </asp:templatecolumn>

thanks