MACD Indicator

[Richard Wells <richwells@xxxxxxxxxxxxxxxxxxxxx>]

Here's a simple question that displays my ignorance!
In using the builtin Metastock MACD Indicator, I see it combines the
MACD signal (set at 9 days) with a Moving Average Indicator.  I want to
use either a 8,17,9 for buys or 12,25,9 for sells.  How can I do that? 
The moving average properties mentions vertical & horizontal, or some
such confusion. Thanks