Just the numbers, Like you showed before but without the spaces.

For example if your file contains

1,2,3,4,3,2,1,5,3,2,4,1

The timer would fire case 1 the first time the timer cycles, then case 2 the next time then 3 then 4 then 3 then 2 then 1 then 5 and so on

The case statement is code that tells the program to do certain things in the case where this is true. It is basically the same as a bunch of if else statements.

Code:
Select Case X
   Case 1
   case 2
   case 3
   case else
end select
is the same as
Code:
If X=1 then
ElseIf x=2 then
ElseIf X=3 Then
Else
End If