webMethods 9.0 reached End of Maintenance in June 2016 so I would encourage you to upgrade to a more recent version.
With that said, CAF has always provided controls for rendering external scripts and script blocks, so you may be able to make it work, but it just much harder to do.
But, I can not do that work for you.
#webMethods#webMethods-BPMS#MWS-CAF-Task-Engine