Hello, I want to fly from LAX-NYC (prefer LGA/JFK) and have a layover for a night then continue on to MAD, and fly back BCN-LAX.

I could book a OW on AA/UA/US from LAX-NYC for 12.5k, but thought about a layover enroute to MAD if it's available since I will only need to stay a night.
Can you help me with the best use of miles and shortest routing for the NYC flight, MAD and BCN flight. I have the following:

100k AA
100k UA
100k US
100k UR
100k MR

Thanks!