How do I build a wind pipe?

Hello gentlemen

I'm trying to create this "wind pipe". Whenever the player is inside this pipe it'll be constantly pushed to the left. However if the player is pressing the "move right" command the character should be able to move freely but in a slower speed.

I tried to build this using "vector x" functions, but it didn't seem to work D:

Have any of you ever built this or something similar? Do you guys have any suggestions about it?

Thank you for your attention

if player is overlapping pipe

then

player.x=player.x-5

I used the "move forward" function. Worked just as good. Thank you