Trading out for zero liability Lay To Back

[Iswinningaproblem]

I need some help on creating an automated file to perform the following:
I want to LAY a horse preoff and then fire a back bet at 25% bigger in running that will give £0 liability on the selection and a profit when any other runner wins.
The standard trade out BA functions give me the opposite (profit if original Lay selection wins and £0 if he is beaten).

The closest imperfect thing I can figure right now when testing is store the backed price +25% then fire a back bet for a % of net stake, but it comes out different depending on odds, how can I get the optimal of what I am seeking.

Thanks in advance

[Dallas]

Try this
viewtopic.php?f=61&t=13551

[Fluence]

Dallas you're a bloody genius.