change visible prop of buttoncolumn in datagrid

I need to programmatically change the visible property for a button column in a datawindow. I need to do it programmatically because it should be visible in some rows and not in others.

How do I reference the buttoncolumn from within the ItemCreated event?

<aspataGrid id="edgRSVPlist" runat="server" OnSelectedIndexChanged="edgRSVPlist_SelectedIndexChanged" DataKeyField="rsvp_id" OnItemCommand="edgRSVPlist_ItemCommand" AutoGenerateColumns="False" CellSpacing="1" CellPadding="1" PageSize="2" DataSource='<%# GetRSVPlist(request.querystring("EventID")) %>' OnItemCreated="edgRSVPlist_ItemCreated">
<AlternatingItemStyle backcolor="SkyBlue"></AlternatingItemStyle>
<Columns>
<asp:BoundColumn DataField="email_address" HeaderText="Email Address" visible="false"></asp:BoundColumn>
<asp:BoundColumn DataField="Fname" HeaderText="Name"></asp:BoundColumn>
<asp:BoundColumn DataField="Lname" HeaderText="Last"></asp:BoundColumn>
<asp:BoundColumn DataField="rsvp_id" visible="false" ></asp:BoundColumn>
<asp:BoundColumn DataField="sub_id" visible="false"></asp:BoundColumn>
<asp:BoundColumn DataField="e_event_id" visible="false"></asp:BoundColumn>
<asp:ButtonColumn runat="server" Text="<img src=../images/email.gif alt='Email this person' border=0>" HeaderText="Email" CommandName="SendEmail" </asp:ButtonColumn>
<asp:ButtonColumn runat="server" Text="<img src=../images/delete.gif alt='Remove from RSVP List' border=0>" CommandName="remove" HeaderText="Remove"></asp:ButtonColumn>
<asp:TemplateColumn HeaderText="Add">
<ItemTemplate>
<asp:ButtonColumn runat="server" id="btnAdd" visible="false" Text="<img src=../images/add.gif alt='Add to my Sociables Address Book - enables you to send email invitation to people you've met thru the Sociables.' border=0>" HeaderText="Add" CommandName="add"></asp:ButtonColumn></font id="red"></ItemTemplate>
</asp:TemplateColumn>
</Columns>
</aspataGrid>

 

ItemDataBound event of the datagrid,

allows you to access each bound row of the datagrid as it is bound, allowing to access any column, and controls, text whatever is in each row.

Michael