Default command option

Is there a way to change the default command option in Rhino?

What I mean is when I call the command arc for example, by default is asking for the center, start and end, but I always use start, end and middle point, can I change this?

Many thanks.

How are you invoking the command? You could create an alias with the following macro:

! _Arc _StartPoint

A toolbar button with this macro exists in the Arc toolbar.

HTH, --Mitch

Thank you!!