How to update mailchimp list with website customer details

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C#

if i want to update mailchimp customer list from a existing database using c# then how should i start?
there is a website and it has registration option; those who had already registered and updated in the database i want to add those in mailchimp account.
can anyone guide me how should i progress?

Here i get a resource that is a file named "PerceptiveMCAPI.dll". It is mentioned that this file may help to make a .net console application that will run once to synchronise data with the mailchimp server.
But i don't get any effect using this as a resource. Still getting an error like

"Warning 4 Namespace or type specified in the Imports 'PerceptiveMCAPI' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases."


Thanks in advance