CS syntax for stand-alone python

Hi,

I'm trying to run;
ASCII3D_to_Feature_Class

The geographic coordinate system I require is 'GDA 1994 MGA Zone 55'

I've tried
CS = "Coordinate Systems/Geographic Coordinate Systems/World/GDA 1994 MGA Zone 55.prj"

But, I get the error;
>>> ERROR 000622: Failed to execute (ASCII 3D to Feature Class). Parameters are not valid.
ERROR 000628: Cannot set input into parameter input_coordinate_system.

Some help with the correct syntax would be greatly appreciated

Cheers