[pstricks] newpsfontdot

[Adam Fenn]

In the following example I would like the new \psdot to be centred  
precisely at (2,2). I see that changing the numbers between the square 
brackets moves the cross but how do I work out what they should be?

\input pstricks

\newpsfontdot{cross}%
[2 0.0 0.0 2 -0.78 -0.7]{ZapfDingbats}{<40>}

\pspicture(4,4)
\psgrid \psdot[dotstyle=cross,dotscale=4](2,2)
\endpspicture
\bye

Adam Fenn