Adding 2 things to a placeholder

After receiving some help I was able to fill a placeholder with a group of 50 dropdownlists. 

Now, I need to do 2 more things:

[1]I need to fill up each unique dropdownlist with a unique selection and then 3 duplicated selections [EXAMPLE]:

<asp:ListItem value="variable_PreviousSelection">variable_PrevSelection</asp:ListItem>

<asp:ListItem value="1 Go to the complete details ...