Locking a cell that contains a formula that has provided a result

[redders]

Howdy. This is probably perfectly simple but I just cannot find a way to do this.

In the attached sheet I has some data on Sheet1. What I am trying to do on Sheet2 is look at Sheet1 and if the corresponding cell contains any data, then I want the cell on Sheet2 to show "-----" and then be protected from the user being able to edit it. If the cell on Sheet1 is blank then the corresponding cell on Sheet2 needs to also be blank BUT be editable by the user.

I am using a simple =IF(Sheet1!B2="","","--------") on Sheet2 to get the data from Sheet1 but the problem is if it returns a value then the cell remains editable.

Thanks for your assistance.

[redders]

Sorry, the file is not attached so here it is.