No.

Maybe if you had a machine shop equipped to do precision prototyping work and a few days worth of time to experiment you might make something work, but even then I doubt it. The shifters are disgned to be held in gear with cable tension from the derailleur, and that tension is partially balanced out with a return spring inthe shifter. All mechanisms inside are designed with this in mind and would have to be rebuilt or modified to work backwards.

If I were you I would consider the following solutions (in order of preference):

1. Return derailleur and get high-normal style
2. Replace shifters with continuous-rotation style like bar-ends shifters w/Paul's Thumbies or IRD Thumbshifters
3. Replace shifters with continuous-rotation style like Gripshift