Creating piwik plug-ins by PHP

Hello,? Currently we are using Piwik, open source web analytics software. ( please visit [login to view URL] to get more information) Piwik is a great open source software but it does not give 100% satisfaction in terms of funtionality. There are certain missing functions we need in Piwik. in short, we want to have a data with "session id" whereas piwik does not provide data with "session id" information. I will provide details after. thanks.