Using Date and Occurence count to create a name

[DatabaseIntern]

Okay, So I am fairly familiar with access, but I having an issue that I think should be fairly simple to figure out.



I am cataloging MOC (management of change) forms from 3 different power plants, I would like the name to automatically create itself as the intials of the plant, followed by the date created, and heres the kicker, followed by the sequential number of which MOC this is (like how many have been done this year) formatted with 4 digits.

Example, it is the second MOC form the year 2013 at plant "A" - todays date is 7/11/2013

I want to be able to automatically fill out the name as:

A-201307110002 ( that is Plant A, year 2013, month 07, day 11, MOC# 0002 AT PLANT A) I am having no trouble with the date, or really even the plant part, but I cannot figure out how to get that last number in there. Any help would be appreciatted, I will also answer all questions as I am sure this is confusing.

Thanks in advance!

BTW my DB is a very simple one dimension list of MOC number, sponsor, etc...

[rpeare]

let's assume:
your form name is TESTFORM
your plant name field is called PLANT
the table storing your information is called TblTest
The field storing your label in is called MOC

the code to create your number would be something like

Dim sMOC
Dim sMaxMOC

sMOC = Plant & "-" & DatePart("yyyy", Date)

sMaxMOC = DLookup("Max([MOC])", "tblTest", "left([MOC], 6) = '" & sMOC & "'")
If IsNull(sMaxMOC) Then
    sMOC = sMOC & Right("0" & DatePart("m", Date), 2) & Right("0" & DatePart("m", Date), 2) & "0001"
Else
    sMOC = sMOC & Right("0" & DatePart("m", Date), 2) & Right("0" & DatePart("m", Date), 2) & Right("0000" & CInt(Right(sMaxMOC, 4)) + 1, 4)
End If

MOC = sMOC

you'd have to run this whenever you changed the plant