You do
not need a control number. Erase it and leave it blank.
That is just a number that the payroll team uses to identify
your W-2 for their system purposes. This is not something the IRS needs, so as
long as you input something in this format, you can proceed.
Just
put in that combination of numbers in this specific format 5 digits, space, 5 digits (for example, 12345
67890). Do not enter any letters, only numbers.