Unicef is helping to provide water, sanitation, education and nutrition, as well as supporting child protection.
Money raised by Charlie will go towards its Haiti Earthquake Children's Appeal.
Along with donations, Charlie was flooded with messages of support.
One donor said: "Well done Charlie - you are an inspiration to us all."
A donor who read about Charlie's appeal in New Zealand described his ride as an "awesome" act of kindness.
Another donor said: "We're cheering you on from Hong Kong."
David Bull, Unicef's UK executive director, described Charlie's ride on Sunday as a "little seed" which had rapidly grown into something much bigger.
"This is a very bold and innovative gesture by Charlie that shows he connects with and not only understands what children his own age must be going through in Haiti, but is also wise enough to know that he can help them," he said.
"The little seed - his idea - that he has planted has grown rapidly and his is a place well-deserved in the humanitarian world.
"On behalf on the many children in Haiti, I thank Charlie for his effort."
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