Aligning an edge flange to and existing flange

HI all,

Im having an issue, well I'd like to know how one of you would skin this cat.

I have a flange I would like to create, though I would like to align it with and existing edge flange on another plane.

I do not want to guess , I want to kjnow that once it is cut it will but up perfectly fr welding.

Ive never had this issue becasue I have never had 2 edge flanges have such an awkward intersection.

Please advise

SolidworksSheet Metal