How can I protect only selected areas of a spreadsheet.

Hi Gill, Welcome to the forum, thank you for your post, in answer to your question, Excel works the other way round, rather than protecting only selected areas in your worksheet, Excel only allows you to un-protect areas but to protect everything else, I know this sounds a little back to front, however it allows users to only enter into those areas where they are supposed to. To "Un-Protect" areas; select the area/areas (use CTRL key to select multiple ranges) to be allowed entry/edit information, go to menu command Format>Cells>Protection, deselect the tick box Locked and Click OK.
The to apply the protection, go to the menu command Tools>Protection>Protect Sheet, apply password protection if required and Click OK.
If you now try to enter data into any cells that are not "Open" you will get an error message. I hope that helped, best regards Pete