Reports: Emirates eyes new first-class product | Components content from ATWOnline
Looks like Emirates fleet is planned to grow by total of 32 aircraft by 2020.
Assuming 18 Crew per aircraft in average that would translate to around 300 more captain positions by 2020. Adding in attrition of 3% for 5.5 years would add around 300 more captain positions.
It looks like 600 upgrades in the next 5.5 years.