You can do that with programming. There's an example he

http://www.contextures.com/excelfiles.html

Under Data Validation, look for 'DV0017 - Select Multiple Items from
Dropdown List'


Lori wrote:
I have created a worksheet with several drop down boxes. Is there any way the
user can select more than one item in the drop down box ?


--
Debra Dalgleish
Contextures
http://www.contextures.com/tiptech.html