I'd recommend don't do that.

They make periscope vents. That might solve your problem. Be aware that since they are rigid (I think) that they are noisier than the flex tube type vent.

shouldn't use "flex" tube vents...

the ridges collect lint

I looked at the periscope vents. The problem is the way the back of the dryer is constructed and the position of the vent exiting the dryer.

The periscope gets me about an extra half inch to inch over the 4" pipe. There's a gap to the side of the vent exit that a 3" pipe could recess into nicely, which would give me even more.

Kind of a poor design if you ask me.