[pstricks] Using \nccurve with Postscript coordinates inside \pscustom

[Christoph Bersch]

Hi,

I want to use \nccurve with Postscript coordinates inside \pscustom. 
Using \pccurve does not work, because inside \pscustom no new nodes can 
be defined with \pnode (as is done internally in \pccurve), the 
following one does not draw any curve:

\documentclass{article}
\usepackage{pst-node}
\begin{document}
\begin{pspicture}[showgrid=true]
   \pscustom{\pccurve(! 1 1)(!3 3)}%
\end{pspicture}
\end{document

This is a heavily simplified version of the original problem. There is 
no way to define the nodes outside the \pscustom scope.

Is there any viable solution for my problem?

Thank you,
Christoph