how to lock a field in excel?

I want to create a file for my colleagues to fill in

But some fields they should not touch!
(formulas etc...)

How you do that?

You need to protect the worksheet under the Review tab click Protect Sheet. (Setting a password is optional.)

All cells are locked by default. Highlight the cells you want to be able to be interacted with, hit Ctrl+1 and go to Protection, and turn off the lock on those cells. Now use Protect Sheet, and all the other cells will be locked.

Thanks!
Had to figure out the order of setting the lock and THEN protect sheet...

That worked really well!