WSPLOT.SPE is an extention-file for SPSS. It is mentioned in O'Brien & Cousineau (2014). Represention Error bars in within-subject designs in typical software packages. The Qualitative Methods for Psychology.
Indeed, Matthew Grizzard is spot-on here! You really have to poke around, because the WSPLOT bundle is buried in a .zip file in those appendices. I included it below, to help the process along.