Locking of a row dependant on VLOOKUP data

I am building a worksheet containing rows whose cells depend on a VLOOKUP formula to take data from another worksheet. Once extra information has been entered by the user these records are then used to print a document.

Once printed I need to be able to lock the record from any further editing caused either by direct editing or from editing of the worksheet containing the VLOOKUP values.

It strikes me that a check box or cell with a true or false value for *document printed" could be utilised to lock the row, however I could use help with either the necessary code or the built in feature to achieve this.

Regards to all.

Paul