Laying off an SP bet

[scattydove]

Hi

My trigger is currently:-

=IF(AND($R$1<=60,AX5=1,F2<>"Suspended"),"BACKSP","")

Is there a method to lay off that bet in running, preferably at the square root of the SP

e.g £20@4.0 would trigger a lay bet at 2.0 to win back £20

And to have a further lay bet in there, at a different stake, say £50 at 1.2

Many thanks in advance

[scattydove]

NB : if the above is not possible please could you suggest the closest alternative, thanks