Hi
In your trigger price field if you use the word "best" without quotes it will lay at best available price.
Use this with the following settings:
settings > betting options > when laying at "best" price, offer a price that is x ticks above current lay price
settings > betting options > when laying at "best" price, don't offer a price higher than y
also have a look at the r_ticks() function which will offer a price x ticks above or below, for example:
in the price field: r_ticks(lay_price, 5) will lay 5 ticks higher than current best lay price