Andrew, who founded the Pitch@Palace initiative to connect start-ups and fledgling companies with potential investors and industry experts, told the businessmen and women that the event was about raising their profile.
The event saw 42 companies, which have been successful in three regional Pitch@Palace finals in Sheffield, Belfast and Cornwall, make a three-minute pitch to a panel of judges at the Harwell Space Campus, near Didcot, Oxfordshire.
The Duke told the pitching companies, 15 of whom will be chosen for next month's national final: "Boot camp today is about raising your profile so Pitch@Palace will have a better idea of how we can make a difference to your business.
"This is about networking, raising your profile, finding your place so you can fit into the supply chain. Today is all about you."
The day long event will give the entrepreneurs the opportunity to hear from leading industry experts and Pitch@Palace alumni, as well as receiving support and mentoring.
Now in its third year, this is the sixth Pitch@Palace initiative to be held and it has the theme of technology.
Among those pitching was a business called Ding which has developed a smart doorbell that allows a resident to talk to the person at their front door, wherever they are in the world.
The firm Drenched has created a product for taps which allows hands to be washed with only 2 tablespoons of water while EasyVideo has produced "how to" videos for people with learning disabilities who scan a household item, with a mobile device, to find out how to use it.
The public can get involved in the event by nominating one of the 42 boot camp companies for the Pitch@Palace People's Choice award. They can view a video of the pitches, which will be available on a website next week, and make their choice.