The law requires that you maintain wage registers.
There is no definition of the term. So we need to go by the normal understanding, which means it should be in a hard bound register, from which pages can not be removed or tampered with.
One option then is to paste the printouts into the hard register.
Other option is to bind the printouts every month into a register.
A third option as Jeevarathanam said, is to get an approval to maintain records in a soft copy.
The rules are same irrespective of whether you have 20 or 100 or 1000 workers.