Is there a better way to multiply matrixes from VBA than calling MMULT? I
ask because MMULT does what I need, and is very fast, but when I call it
from VBA to multiply matrixes on various sheets, the function seems to force
that data sheet to become the active sheet.

With the rest of my program I can have a summary sheet in view that keeps
showing progress. When I incorporated MMULT into my VBA though (rather than
my own VBA multiply code) the screen is constantly flashing through all the
sheets. Killing ScreenUpdate stops that problem, but then of course one
can't see the summary sheet updating either. I haven't come across any
other worksheet function, that when called from VBA steals the active focus
like this.

I'm trying to run this strictly from VBA so I can keep AutoCalculation
turned off. That makes things much faster for me, but gets me into this
problem of a fast way to multiply matrixes from VBA.

Thanks.

Bill