drawing a line between two points (-3,2) and (-1,2)

[makubate]

I will like to graph a scatter plot of variables ECAN and Libcom and then draw a horizontal line between the coordinates (-3,2) and (-1,2). Do I need to use REFLINE or just LINE? Is it GRAPH or IGRAPH. Please help.

I used the follwing codes but REFLINE gives me a line that passes through both (-3,2) and (-1,2) and other points of the form (x,2).

IGRAPH
/X1 =VAR(Libcom) TYPE=SCALE /Y =VAR(ECAN) TYPE=SCALE
/REFLINE  ECAN 2
 /SCATTER .