Can't figure out how to do some stitches

I have a pattern that is supposed to produce "arrows" but I can't figure out how to do it. The pattern says to " skip three stitches, then triple crochet, then, behind the triple crochet, double crochet into the three skipped stitches. On the next row, you skip three stitches and then triple crochet, then over the triple crochet you double crochet into the skipped stitches. I cannot get it to look anything like the picture. Pls. tell me how to "go behind the triple crochet. Is it behind the work?