You have a couple of options:
1 - Create an Intellisync plug-in that will sync your contacts. This needs to be done in C++. The entries will appear in the device's calendar app.
2 - Transfer the data via USB. We've done this for one client where a desktop-side app communicates with a device-side app and transfers the data via USB. The entries appear in the device's calendar app.
3 - Write a server-side app that pushes the entries to the device. However, for push, you will need a BES which I'm guessing you don't have.