Enabling multiple selections in same cell from dropdown menu
 

I am setting up a database off of excel 2007 and want to be able to
select multiple options from a drop down
menu in excel. Is there anyway to do this?

i.e, options are A, B, C, D in drop down

I want the field to be able to have A, B in same field

Also, how do you set up a form in Access 2007 that will allow the same?