Allow breakdown of per diem for meals provided

Allow breakdown of per diem for meals provided

Would it be possible to break the per diem down into what you get for each meal.  The reason for this is we want to offer per diem but if a meal is provided by a customer or sales we need to remove this from the per diem bucket for that day.  
We break down our per diem into:
- Breakfast - 14%
- Lunch 30%
- Dinner 30%
- Incidentals - 25%

Then if an employee has his dinner paid for by a customer then we only give them 70% of the per diem value.  Right now we have to do this in excel and then we just post a single expense line item for the amount they are owed (with a pdf of the excel as the receipt).