Ok, I've found a solution to this.
The solution is
Here
You just need to create a new shortcut to "C:\Windows\ehome\ehshell.exe" and then add the switch "/entrypoint:{AppID}\{GUIID}"
You get the AppID and GUIID using the steps in the post above. Once done, the shortcut with launch straight into your chosen Media Center Plugin.
For example, I now have a shortcut to
"C:\Windows\ehome\ehshell.exe /entrypoint:{C3B3A465-5FAD-477F-8B16-2022B2ED3B08}\{C3B3A465-5FAD-477F-8B16-2022B2ED3B08}" (without the "")
This launches directly into the PowerDVD plugin within media Center.
It may be of use to someone else or maybe it's just me...