say, i have a simple buy signal from metastock:

signalBuy:=Cross(10,Stoch(Close,9));

when the signalBuy triggered, i'll buy one order manually. wat i need to do is to fill an stop order (in the program provided by my broker of course) the stop price, which is the roughly candle's L price if stoch drops to 5 and submit automatically.

so my question is:
1) how to calculate the stop price which should be calculated only after signalbuy triggered and estimated L if stoch <=5
2) any simple way to fill the stop price in program from my broker and submit automatically. i was told there are some util which will automate form's filling and mouse click but where i can get the stop price which is calculated inside metastock

thanks a head for any possible helpful hints