how to modify width of errorbar in proc template scatterplot?

[master_jiang]

Does anyone know how to modify width of errorbar in scatterplot with discrete X-axis and use line instead of symbols to display estimate?

The target figure is like

There are three lines while the middle one is the estimate such as 0.8 and the upper line/lower line are value of CI such as 1.0/0.6.
My template code is like this:
proc template;
define statgraph ratio;
begingraph/ subpixel=on designwidth=15.5 in designheight=7.4 in attrpriority=NONE;
layout overlay/
yaxisopts=(type=log label="ratio" logopts=( tickintervalstyle=LOGEXPAND base=10 tickvaluelist=(0.1 1 10) viewmin=0.1 viewmax=10 ) )
xaxisopts=(name="xaxis" type=discrete discreteopts=(tickvaluefitpolicy=split tickvaluesplitchar="+")) ;
scatterplot y=ratio x=groupa/subpixel=off jitter=auto JITTEROPTS=(axis=auto width=0.85)
markerattrs=(color=darkred size=10pt symbol=triangledown)

markercharacterposition=left;
scatterplot y=ratio x=groupb/subpixel=off jitter=auto JITTEROPTS=(axis=auto width=0.85)
markerattrs=(color=blue size=10pt symbol=triangle)
markercharacterposition=left;
scatterplot y=gmr x=groupa/ERRORBARATTRS=(thickness=2 color=black) yerrorupper=upp yerrorlower=low index=index
markerattrs=(color=black size=10 symbol=trianglefilled)
;
referenceline y=0.68 / lineattrs=(pattern=3);
referenceline y=1/lineattrs=(color=black pattern=dot);
/* drawline x1= 1 y1=1 x2=5 y2=1 /drawspace=wallpercent; */
endlayout;
endgraph;
end;
run;

What I got is like

The length of errorbar is shorter and I cannot find a way to draw a line with specified length to replace symbol to display estimate. Does anyone know a solution?

[master_jiang]

I'm unable to upload screenshot....... sorry for that

[ballardw]

With a scatter plot you cannot "replace" markers. Something will be there and I am not sure what you intend to replace it with. If your concern is the marker is big enough that it is obscuring the errorbar line then make the markers transparent(MARKERFILLATTRS=) and possibly the marker size smaller (SIZEMAX=) and use a non-filled marker