Ron may be Dutch, but his website is in English.
If not familiar with VBA and macros, see David McRitchie's site for more on
"getting started".
http://www.mvps.org/dmcritchie/excel/getstarted.htm
In the meantime..........
First...create a backup copy of your original workbook.
To create a General Module, hit ALT + F11 to open the Visual Basic Editor.
Hit CRTL + r to open Project Explorer.
Find your workbook/project and select it.
Right-click and Insert>Module. Paste Ron's code in there. Save the
workbook and hit ALT + Q to return to your workbook.
Run or edit the macro by going to Tool>Macro>Macros.
You can also assign this macro to a button or a shortcut key combo.
Gord