IF the ONLY time that the spreadsheet is being opened is through your program, then it would be very simple to use the SaveSettings and GetSettings methods in VB.Asign the number from GetSettings to a global level variable, then before you actually assign to SaveSettings, get the number from the global variable add 1 then save it back to the registry. Doing this in VB obviously will not work if the spreadsheet has the ability to be opened at any time other than through your program. Look in Excel help for save/get settings .. perhaps there is a method to accomplish the same thing that is exclusive to Excel.