Tutorial below :)
Start by creating a sketching on the front plane. Make sure you relate the center point to the origin. When done, just exit the sketch.
Next select the top plane and create a new sketch.
Start the sketch from the origin point and create a sample line. Exit the sketch after done.
Select the sweep option from the boss/base tab.
Select the circle as the profile and then the snakey sketch as the guide. Congratulations on your new sweep! Keep experimenting to try different sweeps :)
Thank you for explaining! Been beating my head for hours...