The reason that 3 copies of the controlfile are used is because it is such an important file. Withou it, you can't start your database.
You can actually start your instance/db with 1 controlfile, but it is recommended that you keep at leaset 3 copies on seperate disks.
To recreate your second controlfile :
shutdown database.
Use OS commands to copy controlfile to another destination.
edit your init.ora with paths to all controlfiles(including the one you just created)
restart database.
Once you have eliminated all of the impossible,
whatever remains however improbable,
must be true.