Format cells, but not delete

[excel311]

Hello there,
Can anyone help on the following:


I have a protected worksheet, and I need the users to be able ONLY to:

- enter text in a given range, lets say "A10:F20", by writing or pasting text copied from another program,
- format the range (colour, font, etc);

What I DON'T want them to be able to do, is DELETE the text they have entered.

Using "Protect Sheet - Allow users to edit range", and ticking the "Format cells" allows them to delete the text in the range.

Thank you