I need to set variables in a multi-configuration system.  The manual does NOT explain how to do this!

From the manual:  

“SETVAR config, M, status, operand”

and down below:

“If the code is M, then the syntax for this command is as shown under "syntax" above.”

This is quite useless circular logic!  It just points me back to the top with no resolution or answer!

What do I put for an “operand” if I want to vary curvature 8 on configuration 3, for example?

SETVAR 3, M, 1, then what?  How do I tell it curvature 8?