this sub is called, when a different cell is selected (or a different row on FullRowSelect).
BUT this event is not documented yet, because it is a little buggy. After selecting a different cell or row, the SelectionChanged sub is called twice most of the time. If this doesn't matter in your application, I think you can use it.
If you read this thread, please check why the SelectionChanged event behaves buggy like this. Maybe you can fix it!
as the SelectionChanged event is not always called twice, even a separate counter wouldn't solve this problem. So I think the only way is to fix the bug in the dll...
@Filippo again: Please read this thread carefully and post a small answer if you can/can't/will/won't fix this bug in your dll. As an alternative you can post your actual source code (which includes your last additions) so someone else could be so cute to fix the bug. Thanks!