Lewberry6, welcome to Flyertalk, and welcome to the BA forum. It's good to see you here and I hope that you will continue to participate here.

Not only is this not possible, it's also an immutable fact of life that Avios redemptions and revenue tickets cannot be combined in any form. In addition to the suggestions above, what you could do is look at returning via the USA, using some Avios to get there. Iberia does one ways from USA to Madrid for relatively sensible sums. I would think about getting something on redemptions which is vaguely acceptable, and then checking on a daily basis for a better redemption option for the return sector. You never know....