"serving as a command" is correct and usable in written English.
You can use it when you need to describe something as being an authoritative instruction or direction. For example: "The President's statement served as a command for the military to mobilize for battle."
These included configuration to serve as a command ship (SSCN) for a fleet or force commander, an advanced sonar scout for the fleet, a Regulus missile submarine (SSGN), or a minelaying submarine.
In the province of Phangnga, some five hundred miles south of Bangkok, a temple known as Wat Samakhitham served as a command center in the….
In the offices of the British Council, a large auditorium serves as a command center to manage response efforts in the city.
B6 CHANGES IN JUSTICE -- Attorney General John Ashcroft established a task force to serve as a command structure for prosecuting terrorism cases and preventing new attacks.
In the province of Phangnga, some five hundred miles south of Bangkok, a temple known as Wat Samakhitham served as a command center in the tsunami relief effort and as a shelter for more than eight hundred people.
General Richards, chief of the defense staff in Britain, spoke in an interview at NATO's southern headquarters in Naples, Italy, which has served as a command center for the attacks.
By Eliza Griswold In the province of Phangnga, some five hundred miles south of Bangkok, a temple known as Wat Samakhitham served as a command center in the tsunami relief effort and as a shelter for more than eight hundred people.
The four Hercules would be accompanied by two Boeing 707 jets, one to serve as a command post, the other as a field hospital – to treat what they anticipated would be many injured.
On the 20th floor of the New York Catholic Center in the Turtle Bay section of Manhattan is a cramped conference room that will serve as a command center for the visit.
Fleming liked to take notes in it, and it once served as a command station when Prime Minister Anthony Eden of Britain visited Goldeneye in 1956 (another boon for Jamaican public relations).
