Long story short: The wife bought an Over the range Microwave with a built in fan that can be ducted to the outside. My present cooktop has a down draft vent that I was going to try and reuse the exterior wall hole if possible. This is an exterior wall.

To my surprise, when I opened the sheetrock above the cooktop to work on the ducting for the microwave, a 1/2 copper pipe going to the second floor was dead centered staring back at me ! This pipe goes all the way down to about 12" inches off the floor and then does a "T" and goes through the studs on both sides. The down draft vent duct is right below the "T".

At this point I am abandoning trying to use the existing duct outlet at the bottom of the exterior wall because of the pipe. So I want to duct the microwave horizontally straight through the wall, the copper pipe is dead center between 2 studs 16" apart.

I was thinking to just use 4 90 degree copper elbows and route it to the side of a stud for 12-18" and then back out to the center. The guy at the big box store was telling me to use a sharkbite 18" flexible ss braided hose, but I don't feel comfortable having a braided hose inside a wall. I feel better with rigid pipe - he was then suggesting using the sharkbite rigid elbows, that would make life easier for me, but I have no issues with just soldering, and usually when I take the easy way, it comes back to haunt me.

What is the best way and method you would use to re-route this pipe?

I still cannot believe they placed a pipe deadcenter behind the cooktop!