betting to win a fixed amount

[garythegoony]

Hello,
Is it possible to bet using BA where the software automatically alters your staking to win a fixed number. I know the staking modes are stake, liability and payout but what i am looking to do is being able to click so my lay works to a liability and the back wins the same amount.
For example, i would like to back a horse to win £100, so at 11.0 it would stake 10 pounds,at 2.0 it would stake £100 etc.
The lay bets would all be to the same liability of £100.
The idea for me is that i lay a horse and can take the exact liabilty away when the price drifts or back a horse and lay back the amount it wins me but at more favourable odds.
I hope this is clear enough.
Many thanks in advance

[2020vision]

I would love to see this too - been wanting it for ages...

I nickname it as "Target" - ttfn, Michael