Input box and add rows (tricky, for me at least)
 

I have a named range (a1:a10) = "Name"
I have a right click function that when used within this range a menu
appears asking to Add or Delete. (The menus are disabled if the user clicks
anywhere else on the spreadsheet).
As of now, if a user right clicks on cell A3 in chooses Add, another row is
added above the selected cell (it is blank). Now the named range "Name" is
A1:A11.

What I would like is for an input box that can accept one or more variables
(comma separated. For each item entered, a new row will be inserted and the
cell will be populated with an item. Example:

A2= Bob
A3= Sue
A4= Joe

A user right clicks A3 and chooses add. An input box will appear: "enter
name(s) separated by comma. User enters: Pete, Mary, Ryan then selects OK

The results will look like this:

A2= Bob
A3= Pete
A4= Mary
A5= Ryan
A6= Sue
A7 = Joe