The Magpies were held to a 0-0 draw at St James' Park, but they believed they had two perfectly good goals chalked off by the officials.
Cisse was denied by the offside flag either side of half-time against an impressive Metalist team.
Cisse insists that he and his team-mates will swallow their disappointment and do everything they can to ensure those contentious decisions do not prove too costly.
The 27-year-old said: "I think they were both goals, but it is down to the linesman. He said 'no' and once he's made his decision, it's a no.
"There's nothing you can do. It's so frustrating. We should be talking about a win. That would have been very, very good for the team.
"The other team tried very hard and denied us. We just couldn't get the win.
"But we can win the second leg and we will be going over there to give it everything. We are confident of still doing the job and getting through."