Hi Nancy,
I did it in this way:

stim,loc,time
~left word,"256,0,1",0,
~right word ,"768,0,0",500,
dot,"256,0,1","rt:30,76",*

or better:
~left word,"256,0,1",0,~right word,"768,0,0",500,dot,"256,0,1","rt:30,76",*
(LOC is in quotation marks, I guess that's the important fact for you)

256 and 768 are the pixel-locations of the stimulus words, then, as you can see, I used a "clear screen" in the the first screen (it's the 1, a "screen" consists of of a stim-loc-time pattern) and then a zero for the next screen (another stimulus is added, but if you use a zero value for the second stim than the first and the second stim are presented at the same time, at least if you use a zero value in the "TIME" column). Both words are presented for 500ms (you just put in the presentation time in the LOC of the second stimulus). Straight after that, the screen is cleared and the dot appears.

Maybe this helps. I used the code in a study and everything worked fine.
Best,
Tom