Use Excel ISNUMBER Function to verify if a cell contains a non-text value. If that value is non-text it will return TRUE, else FALSE.
In the below example, I have used this function with IF Function to deliver a message to the user if a non-text value will enter into the cell.
To learn more about Excel ISNONTEXT Function you can check Microsoft’s Help Section. And, if you have a unique idea to use it, I would love to hear from you.