Let's give it a go.
Westbound RTW.
NYC (DL/AM) MEX
MEX (AM) NRT
NRT (NW) SIN
SIN (CZ) CAN
CAN (CZ) DEL
DEL - BOM "overland" (i.e. buy an oneway domestic ticket)
BOM (AF) CDG
CDG (AF) NYC

Just purchase a MEX-EZE roundtrip on top of it and you're set.
Anyone able to pull the exact timings to ensure connections are workable?