Without any user interaction" - so that's not true, user will have a combo box to (interact) choose 01, 02, 03, 04, or 05 from...
it looks like you can still use a table like this:
[pre]
PK Castumer_Number Seq_Number Seq_N2 MyDate
1 1 1 1 4/6/2015
2 2 1 2 4/6/2015
3 3 1 3 4/6/2015
4 4 2 1 4/6/2015
5 5 2 2 4/6/2015
6 6 2 3 4/6/2015
[/pre]
And concantinate and format Seq_Number (like I have in my previous post) and Seq_N2 for any given day to give you the 01003 sequence number. With any new Customer it is easy to add to this table, just use [tt]MAX(Seq_N2) + 1[/tt] to get the next record/sequence.
Have fun.
---- Andy
A bus station is where a bus stops. A train station is where a train stops. On my desk, I have a work station.