how to enter free-form text in cell with drop-down-list?

I'm having to do a little bit of user data validation in Excel which will be used for application upload. I have a list of values (LOVs) that I'm providing in a drop down box in an Excel. That's easy.

Is there a way to also allow for free form text in the drop down list cell? Excel tries t开发者_StackOverflow中文版o validate it against the given LOVs. I don't need the user-entered text to become part of that LOV, just that it is possible to 'override' or put additional text in there instead?

In the Validation dialog, go to the "Error Alert" tab and uncheck "Show error alert after invalid data is entered".