[2008] User Rights Question

Here is the scenario I have:

I have an application that is running as SYSTEM. We will call it "UpdateEngine.exe".

Under application events, if another instance is already running, it will pass command line arguments to the the instance that is already up.

For example if you type "UpdateEngine.exe /shutdown" it will pass "/shutdown" to the first instance of the application.

Here is my problem:

When the second instance, which is running under user context, tries to pass the command line arguments to the first instance that is running under SYSTEM, the second instance crashes.

Is there a way I can pass information to an application that is running as SYSTEM?