Generating next number

I am trying to set up an inventory system for my wife's online sales business. She needs to add an item number to her products so I have established a system that will be 000-00000-00000000 format. The first three numbers and the second five are for tracking location and selling location. The last eight will be used as an item number. Once we use the 0000001 we don't want to use it again. How can I search the row of cells with the item numbers and find the next available number?

Thanks in advance.

So since she is still getting started with the system, some items have numbers and others do not. The format going forward will be a combination of letters and
numbers with the last eight spots all being numbers. So based on the last eight numbers I want to be able to find the next available number.

So if column a is the item numbers it looks like below. U am only using the last eight numbers. So in this case I want to generate my next number as 00000003

A

row1 m12-0038-00000000
row2 w9-23-00000000
row3 -00000000
row4 m100-epf00-00000001
row5 w300-ep000-00000002

I have already made a macro to make blank cells -00000000 so there will be 8 numbers from the right.

Thanks

Try this

PHP Code: 

Public Function Next_Number(rng As Range) As String
Dim cel As Range, temp As Long
For Each cel In rng
    If cel.Value Like "*########" Then
        If CLng(Right(cel.Value, 8)) > temp Then temp = CLng(Right(cel.Value, 8))
    End If
Next
Next_Number = Format(temp + 1, "00000000")
End Function 


Or try:

=TEXT(AGGREGATE(14,6,--RIGHT($A$2:$A$9,8),1)+1,"00000000")

So regular

Cell C2 formula

HTML Code: 

I tried the Lookup function but I think since the numbers are not all the same format it only gives me back a value of 1

You're Welcome. Thank You for the feedback and for marking the thread as 'Solved'.