This command replaces whatever is on the screen at a specific spot ([row][,column]). If no row or column is specified, the default is the upper left corner (0,0). If the picture is less than the full screen, only the spot at which the picture is placed will be removed. If you do not want anything replaced, use RclPic instead…
260 - Domain error happens when the [row,column] argument is outside the screen range..
960 - Undefined variable happens when the picture variable specified does not exist..