>Can macro substitution (&) be used in a report?

It depends where you want to use it. I don't think you'll have much look using it as an expression, because & substitues VFP Code, it doesn't make expressions. In that case, use Eval() or (). However, say you store a field name in a variable called lcSubGroup1, and in the DataGrouping dialog you put in "&lcSubGroup1" as the group expression, that will work.