The problem I see with using the 'InStr()' funtion is it would also return a value on a partial match, for example if the target was 13 it would match any value with a 13 in it 13100,13200,13300 where you may be looking for an absolute match. My approach to this would be to use an Array to list the allowed values and then use a function to return true or false depending on if the value was in the array.
You would need to define the array variable at the Module level for availability to the function in the same module. If you dim it in the procedure you would need to pass both the test value and the array to the function.
Code:
Dim ArrayVals
Sub CeckArray()
ArrayVals = Array(13200, 13300, 12003, 15023, 17894)
' start loop here to check wksheet
If InArray("12003") Then
Debug.Print "Value is in Array"
End If
End Sub
Function InArray(strValue)
Dim i
For i = 0 To UBound(ArrayVals)
If ArrayVals(i) = CStr(strValue) Then
InArray = True
Exit Function
End If
Next
InArray = False
End Function