You can use GUI specifiers to enclose an entire do...except statement before individual statements, but you cannot use GUI specifiers before the except clause.
// legal: do mswxp Verify (expr1,expr2) mswin7 Verify (expr3,expr4) except mswin7 reraise mswxp if (ExceptNum () == 1) Print ("err, etc.") // NOT legal: mswin7 do Verify (expr,expr) mswxp except reraise