[pstricks] Accessing key/value parameters set using \psset in custom macros?

[Richard Hensh]

I'm trying to understand how to write more sophisticated PSTricks macros
using a format that has appeared in this list. 

The following does not work as expected. How can I modify the macro \rjhLine
to ``apply'' all relevant styles that have been set using \psset (see
comments below)? Can someone point me in the right direction? I can't figure
it out!

Thanks
Ricky

\documentclass[10pt,dvips]{article}
\usepackage{calc}
\usepackage{pst-plot,pst-math,pstricks-add}%
%\RequirePackage{pst-xkey}

\makeatletter
\def\rjhLine{\pst at object{rjhLine}}
\def\rjhLine at i(#1,#2){%
    \pst at killglue
    \begingroup
 
\addbefore at par{linewidth=1.25pt,linecolor=red,arrowscale=1.25,arrows=->}%
%    \addto at par{linewidth=1.25pt,linecolor=red,arrowscale=1.25}%
    \use at par
    %\the\pst at toks
    %\the\toks@
    \rjhLine at ii(#1,#2)
    \endgroup
}
\def\rjhLine at ii(#1,#2){%
    \psline(#1,#2)
}
\makeatother

\begin{document}

\def\xmin{-6}\def\xmax{6}
\def\ymin{-6}\def\ymax{6}
\begin{pspicture}(\xmin,\ymin)(\xmax,\ymax)
    \rjhLine[linecolor=green](-1,2)
    \psset{linecolor=blue}
    \rjhLine(3,4) %%%Why isn't this line blue?
\end{pspicture}

\end{document}