Unfortunately, no.
I have been frustrated to no end with the
terrible slow motion
"feature" of PowerDirector.
Third Party software, like "Twixtor", is not available for PowerDirector. I suppose they consider a software that costs six times as much as the video editor would not sell so well.
The best option I have been able to find, is to film at the highest FPS setting your camera will operate at. For example, 60 FPS or hopefully 120FPS.
Then, slow it down by 50% with PowerDirector. Produce. Now possibly, re-import and slow again by 50%. Does not always give decent quality though if you slow it a second time.
The "interpolation" feature I find to be completely worthless in PowerDirector as it makes the quality absolutely horrid.
~Tom~