Creation of plugins through the API require code to be written in C/C++. In order to create a plug-in takes a knowledge of the programming languages and the compliers and tools needed to work in the language.
If you are not able to find anyone here who can help you with this, you would be surprised how many people there are online without jobs and C/C++ knowledge just looking for any paying projects. All the information they would need for the project is provided by EndNote when you request the API.