Starting a rule or servant at certain price

[Dave64]

I'm trying to do something quite simple but I can't quite fathom how

I have a scalping servant that I manually start when I see a runner reach a certain price and I would like this to be automated.

The scenario would be 'check a stored value or price once at 5 minutes before the off and if the condition is met then crack on and run the rule/servant irrespective of the stored value or current price' up until the off.

Any help would be appreciated - Dave