Dynamic Values for RadCombo within EditFormSettings

[Atlas]

I have the following template:

                                <EditFormSettings EditFormType="Template">
                                    <FormTemplate>
                                        <table id="Table1" cellspacing="1" cellpadding="1" width="400px" border="0">
                                            <tr>
                                                <td align="right">
                                                    Company Name:
                                                </td>
                                                <td align="left">
                                                    <telerik:RadComboBox ID="rcbCompany" runat="server" AppendDataBoundItems="true"
                                                        DataTextField="CompanyName" DataValueField="CompanyId">
                                                        <Items>
                                                            <telerik:RadComboBoxItem Text="Select a Company" Value="" />
                                                        </Items>
                                                    </telerik:RadComboBox>
                                                </td>
                                            </tr>
                                            <tr>
                                                <td align="right">
                                                    Role Name:
                                                </td>
                                                <td align="left">
                                                    <telerik:RadComboBox ID="rcbRole" runat="server" DataTextField="RoleName" DataValueField="ApRoleId"
                                                        Enabled="false">
                                                        <Items>
                                                            <telerik:RadComboBoxItem Text="Select a Role" Value="" />
                                                        </Items>
                                                    </telerik:RadComboBox>
                                                </td>
                                            </tr>
                                            <tr>
                                                <td align="right" colspan="2">
                                                    <asp:Button ID="Button1" Text="Insert" runat="server" CommandName="PerformInsert" />&nbsp;
                                                    <asp:Button ID="Button2" Text="Cancel" runat="server" CausesValidation="False" CommandName="Cancel" />
                                                </td>
                                            </tr>
                                        </table>
                                    </FormTemplate>
                                </EditFormSettings>

And I would like to bind the data of the RadComboBoxes in the CodeBehind on the fly.
Which event do I tie into to accomplish this?

I have two events:

    protected void RadGrid1_ItemCommand(object source, GridCommandEventArgs e)
    {
        if (e.CommandName == "InsertChild")
        {
            GridDataItem item = (GridDataItem)e.Item;
            Guid _sysUserId = (Guid)item.GetDataKeyValue("SysUserId");
            GridTableView tableView = (GridTableView)item.ChildItem.NestedTableViews[0];
            tableView.IsItemInserted = true;
            tableView.Rebind();
        }

and

    protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
    {
        if (e.Item.OwnerTableView.IsItemInserted && e.Item is GridEditFormInsertItem)
        {
            GridEditFormInsertItem item = (GridEditFormInsertItem)e.Item;

            RadComboBox rcbCompany = (RadComboBox)item.FindControl("rcbCompany");

            if (rcbCompany != null)
            {
                Database db = DatabaseFactory.CreateDatabase();
                string sqlCommand = "uspGetUserCompaniesAvailable";

                DbCommand dbdbCommand = db.GetStoredProcCommand(sqlCommand);

                db.AddInParameter(dbCommand, "@SYSUSER_ID", DbType.Guid, new Guid(""));

                DataSet ds = db.ExecuteDataSet(dbCommand);
                rcbCompany.DataSource = ds;
                //rcbCompany.DataBind();
            }
        }
    }

neither of which will allow me to accomplish my goal. If I attempt to use FindControl in the item command, the control is always null,
If I use it in the databound method, I get an error on DataBind().

What event would I use to bind data to the RadComboBox's

[Atlas]

My bad,
the problem was that I was using SelectedValue= with Bind. which does not work on insert.