The Pharaohs had an unpromising start to their campaign, having been held at home to a 1-1 draw with Sierra Leone.
However, Doula is convinced that the seven-time African champions are firm favorites to secure Group G first place by the end of the qualifying stage.
"Egypt are the biggest threat in our group," Doula, who saw his men lose 2-0 in South Africa last month, said.
"I believe the battle for second place will be between us, South Africa and Sierra Leone.
"Anything is possible in football. This we proved by defeating a big team like Nigeria to qualify for the CHAN.
"It is therefore not impossible for us to qualify for the Nations Cup. It will be difficult because we're in a difficult qualifying group."
On the other hand, Niger's central defender Harouna Ide believes his side can capitalize on the home advantage in their first three African qualifiers.
"We are unbeatable at home and so are confident of getting nine points from our three matches in Niamey," he stated.
"We only have to work on getting a draw away from home and that should be enough to qualify us for the tournament proper.
"We are drawn in a very tough group that also includes champions Egypt, Sierra Leone and South Africa, but we will do everything to qualify for the next Nations Cup."