A net operating loss deduction is allowed in computing net income for the New York City tax. A carryover or carryback are permitted in the same manner as for federal purposes. The net operating loss may be carried back or carried forward only to the same year as for federal income tax purposes. (from information in 2006 Guidebook to New York Taxes edited by Mark S. Klein ).
See http://www.irs.gov/publications/p536/ar02.html#d0e970 for more federal NOL information.
I hope this is the information that you need for NYC NOL carryforward.