How do I add an OpenOffice macro?

I don’t need to write them.  I don’t need to embed them.  I downloaded some OpenOffice.org macros from the web, and for the life of me I don’t understand what to do with them.  In the morning, when pain meds have faded, it may be very clear, but, be a dear anyway and answer my question: “I have a .sxc file that I want to be able to use in any arbitrary OpenOffice.org Calc document, new or old.  What do I do?”

I can’t bring myself to actually post this on a support group, because this is “so obvious”, apparently.