If you use an MTB shifter with your road front derailleur and crank it will work if it is a two chainring crank.

If it's a triple chainring crank it will work on two of the chainrings but not all three. You'll have to choose between the inner and middle chainring, or the middle and big chainring.

I once put a flatbar on a road bike and I wasn't pleased with the result. Even with the longest stem I felt cramped. It's because a road bike top tube length is 1-2 inches shorter than a MTB top tube, size for size.

Try a moustache bar.