You would just add that 1098 to your return by entering the Mortgage Interest and Real Estate taxes in the appropriate fields.
In the Issuer's name, you can just put the name of the Coop.
You will then enter the Mortgage Interest in Box 1 and the Property (real estate) taxes in that field at the bottom of the screen.
If you have the outstanding principal balance and mortgage origination date, you should enter that as well.
