Daily High & Low--on Intraday Bars?

["Owen Davies" <owen@xxxxxxxxxxxxx>]

The subject pretty much says it.  Does anyone have a formula
they'd be willing to share that captures the day's high and low
when working with intraday bars?  I want to be able to write
the equivalent of, say, Mov(H,10,S) and have it give me the
average of the last ten daily highs on an N-minute chart.  Open
and close can be done with ValueWhen and DayOfMonth()<>
Ref(DayOfMonth(),1 or -1))--I'd welcome an easier way!--but
the high and low still escape me.

Many thanks.

Owen Davies