Develop Office Add-Ins plugin

I am looking for Microsoft Office developer who can help me to create plugin for my system with following requirement: 1. connect to web service and perform login 2. create interface to list templates in the server 3. each template has set of mail merge tags, the user should be able to click and add the tag to the word document 4. User will be able to save the word document to our server directory. 5. User will be able to load any word document from our server.