>>I have a form where I want to put a command button with Click code:
MODIFY REPORT myreport.FRX
Is there some way how I can programmatically enforce that Report Controls Toolbar to appear for the users?<<

First create a new menu (ViewMenu.mpr) via the quick menu method so you can have the basic VFP menu. I then delete all pads except for File Edit View Window (nothing magical about this, just my preference). Then when I get ready to allow editing of report layouts I issue the following commands

Push Menu _msysmenu
do ViewMenu.mpr
MODIFY report (cReport) &&MyReport.frx
Pop Menu _msysmenu

Under the view menu, all the report modify toolbars are available. (Note: The toolbars only are visible at runtime. During design time, only \Toolbars... is available).

Kevin