Design Code:
<asp:CheckBoxList ID="AccCheckBoxList" runat="server" RepeatColumns="8" RepeatLayout="Table" BorderColor="DarkGray" BorderStyle="Dotted" BorderWidth="4px" >
</asp:CheckBoxList>
Code Behind:
string commaString = "3,4,5,6,7,8";
string[] words = commaString.Split(',');
foreach (string word in words)
{
SelectCheckBoxList(word);
}