Locking conditional formatting but allowing entry into the cell??

The default value for all cells is "Locked" so when you Protect a spreadsheet, all cells become locked.

To unlock cells, on an Unprotected sheet, select the range of cells you want to change and right click within the range > "Format cells..."
Then go to the Protection Tab on the opened window and uncheck "Locked" > Okay
Done

1. Set all the cells on the sheet as locked apart from the two in question (use cell formatting - security to do this).
2. Protect the sheet.

No easy way sadly, especially since there are so many different ways to cut and paste. It would require using VBA so the user would have to enable macros when they open the sheet. The best way is through training. Make it clear through training and in the spreadsheet itself (through instructions, data validation input message, and/or cell comments) that they are to either Paste Values or manually input and not to cut and paste.