help with making a dynamic variable

I am trying to make a variable that changes depending on what the user chooses.

i want it to add items to the list and take items away from the list as necessary.

here is the code i am using but it doesn't work.

dim list as string

list = list & item
' this works to add items to the list....but to take them off i use

list = list - item
'but this doesn't work.  is there something i am missing here.  shouldn't it be that simple to make a dynamic list such as this?

thanx for any help you can give me
angel.

thank you for your help this worked.