I have reformatted a form that is used to assess risk. This form has historically been used with no security in place, and as a result, the original form was subjected to unauthorized edits and saved with different information in the form. What I'd like to do is lock all but certain cells (into which data will be placed) and place some protection that would not allow the file to be saved except in PDF format. I have no idea how to proceed with this; I'd truly appreciate some help from those who know.