I saw this video on Youtube, and wanted to know how he was able to add morphs as expressions to add physics to his characters using face keys in this video. https://www.youtube.com/watch?v=ysYk9mXPfXI and this video https://www.youtube.com/watch?v=wjcMlmge2B4&t=62s How is this possible?   

What you know today will be obsolete tomorrow

I hope you realize that it's only for the nude characters (or in g-strings at most).
You'd have to make custom morphs in CC4 for booties like up/down left/right first.
And then after that create .ini puppet profiles (based on some existed) to animate in Face Puppet.
Maybe a little cumbersome, but not that hard to figure out.

I already have morphs from Daz saved (Glute Control) I just need to know how to put them in Face Key. How do i create .ini puppet profiles? Btw still have IC7/CC3 i haven't gotten IC8/CC4 yet

What you know today will be obsolete tomorrow

I just did something better!!! I created butt bones in Blender using the Spring Bones addon, weight painted the areas i needed then baked the bones in afterwards exported into 3DX and into IC7. Thank you for responding though. I may make a Youtube video just for those for reference. 

What you know today will be obsolete tomorrow

Yep, I was about to suggest the same: https://forum.reallusion.com/472037/10-min-Butt-Spring-for-NonStandard-with-Cloth

Funny i used your method before in this video a while ago, and i have a video on my channel following what you did https://www.youtube.com/watch?v=2TPDnIrs5vM but the weight paint in the crotch area of my model was jacked up I figured out a better way to do it now and i still follow the same method except i weight paint in edit mode instead of weight paint mode and it came out great every time

What you know today will be obsolete tomorrow