Excel creating Outlook Appointments

I've got a spreadsheet which has a basic VBA macro which creates an Outlook appointment but have been asked to develop it much further and am completely out of my depth so am looking for help on this and hoping somebody may already have a script they can provide.

The spreadsheet has the following:
1. A name in column B
2. A date in column L
3. A note in column O

There are approximately 100 entries in the spreadsheet today but it changes daily with more entries added and some removed (items removed do not need any calendar entry altering).

What I need is:

1. A VBA macro that can be run across the whole sheet and input an Outlook calendar entry for each line on the date which is in Column L. The subject should be the name from column B and if possible the calendar details should be the notes from column O. The entry needs to be submitted at 8am for all appointments.

2. The macro when run should NOT duplicate any entries in the calendar already.

Any help or scripts that can do the above would be gratefully received.

Regards

Mark