Howdy, Have you looked into the 'data validation' feature
data menu > validation option >
select 'list' from the drop down list under Allow:
and select your source.
if the list data really does neeed to be on another sheet, you can set the source using a named range: =myrange
Hope that helps, its a commonly asked questions, check out the forum search feature
Post back if you have more questions
Regards
Mark