MPlotStencil Xpos.w,Ypos.w[,Colour] ; Plot a single pixel in the stencil to *represent* the [specified] colour

Plots a single pixel within the stencil of the currently used main chunky Bitmap
to /represent/ the specified colour or the currently used ink colour in the
Bitmap's graphic.  If the drawing mode is set to MReMapMode or MSimpleReMapMode
with the MDrawingMode command, MColourMode will be used instead as it is
illogical to try to perform remapping to the stencil.