I think generally for this you would use a varargin type of input to your function.
You can then test the length of varargin and you can pass it on as varagin{:} to another function that also wants those arguments in the same way.
e.g. if you have a function that will call the plot(...) function you can have a varargin argument to your function (even after named arguments) and then just pass it straight to plot as varargin{:} if you know the arguments are in a form that plot accepts - e.g. property, value pairs.
For example I have a function in one of my classes that does the following:
function setGUIHandleProperty( guiHandle, varargin )
if ishandle( guiHandle )
set( guiHandle, varargin{:} );
end
end
which just acts as a wrapper for setting some figure properties.
