macd settings & settings with generic ea

[Forex Trader]

im looking at the generic macd indicator settings, as follows fast ema=12 slow ema=26 macd sma=9
-But-
the generic macd ea that comes with mt4 in the ea properties dialog box has the following,
macd open level=3 macd close level=2 ma trend period=26

My question...how do i adjust the ea to use the macd indicator values??
i want the ea to use the macd indicator values...and be able to adjust both as needed.

thanks, robert s.