Buy/Sell QQQ on NASDAQ signals

["Peter Gialames" <investor@xxxx>]

If there is a thread that the idea of this topic is discussed please point
me to it.

I would like to back test a system that buys and sells QQQ based on signals
of the NASDAQ composite. I am sure I would use the foreign() function but
am unsure on how to implement. For example:

If I get a signal on the NASDAQ for a BUY based on EOD numbers, I would want
to BUY QQQ on the next days OPEN.

If I get a signal on the NASDAQ for a SELL based on EOD numbers, I would
want to SELL QQQ on the next days OPEN.

Any help would be appreciated,
Peter Gialames