What are they using now to generate these numbers? Are you developing new code or what?
You say you need this for a form. Is this how it is stored in the table also?
You may need some code/function to manipulate the data to get what you need.
Code:
Sub test1()
Dim M As Integer, Y As Integer
Dim forDisplay As String, ForSorting As Integer
M = Month(Date)
Y = Year(Date)
forDisplay = Format(M, "00") & Right(Y, 2) 'keep the leading 0 and use string
ForSorting = CInt(Right(Y, 2) & Format(M, "00")) 'sort it by year, then month numeric sort
Debug.Print forDisplay & vbCrLf & ForSorting
End Sub
'Gives following result
'0715
'1507