>I'm not familiar with macrosubstituting. How is this implemented?

I think you probably are, but perhaps not familiar with the word.
You're doing it already, now you need to expand the scope.
Do something like

lcWhereClause = "WHERE INLIST( TheField, " + yourvariable + ")"

"yourvariable" being the one you made be '"A","B"'

Then your SQL is

SELECT ;
FROM TheTable ;
&lcWhereClause ;
INTO

(can you tell I've forgotten a lot)

I expect someone will find I've made an error in this, it's been a long day.

Hope that helps
(ahah! That's probably "HTH")

Mark