How to display items in a dropdown box with one heading for one or more items

I am trying to display results from a SQL query in a drop down box. Here is the code I current have;

Public Sub fillMonthlyDownloadsDropDownList()

Try
conn = New SqlClient.SqlConnection(strconn)
conn.Open()

Dim strSQL = "SELECT distinct d.group_descr, a.first_name, a.last_name, a.user_id, b.email, d.group_id FROM icc_user_data AS a LEFT OUTER JOIN icc_users AS b ON a.user_id = b.user_id LEFT OUTER JOIN icc_users_groups AS c ON a.user_id = c.user_id LEFT OUTER JOIN icc_groups AS d ON c.group_id = d.group_id WHERE (b.user_id NOT IN (249)) AND (d.group_id IS ...