From Longman Dictionary of Contemporary Englishat your commandat your commandUSE somethingif you have a particular skill at your command, you are able to use that skill well and easily a pianist with the keys at his command → command
Examples from the Corpus
at your command• Loyal, bonded silicon brains, hired for cheap and at your command, even if you were only 13.• Try to hire a carpenter with years of experience at his command.• A 12-hour alarm sounds off at your command.• Owen played with all the strength and passion at his command.• How can students cope with the limited resources at their command?• In short, they have an explanatory rhetoric at their command.• And nor would i lead my company to be slaughtered, at their command.• So he would protect himself, with all the weapons at his command.• An old soldier, he had a few choice words at his command. 