How do I create embedded Combo boxes in Excel

Hi,

I work for a company that absolutely forbids the use of MS Access & I'm trying to create a spreadsheet for logging helpdesk calls from our clients. We use standard codes for various parts of the software application we sell & I would like to limit to a drop down list of what users can enter into the fields as we also want to be able to search by them.

I've tried using validations but it's not quite what I want because you can't type letters into the field & then search on them as you would with an Access combo box.

If someone could offer some advice it would be greatly appreciated.

Thankyou,

Michael