Specify the column in
the data file from which the X-axis data are to be read.
This command is a synonym for SETGLOBAL PONGO_XCOL.
Usage:
xcolumn xcol
Parameters:
XCOL = _CHAR (Read and Write)
The column number (counting from 1), or the symbolic name of a
column, from which the X-axis data are read by the READF command. The value "0" means "do not
read these data". []