1. There is no way to include this in the report in QRWIN. QRDOS can do this, though.
2. To exlude the user from modifying the selection criteria in other compiled reports, use a formula for these fields & insert them into the report rather than creating a selection formula. There is no other way, other than unchecking the "Modify selection formula" checkbox in the report's dialogue window after executing the compiled report.

Hope this helps!