>I want to add capabilities to my program to provide users to change report definitions (moving fields, add text, paper format, changing fonts) from within a program.
>
>With
> set reso off
> modi repo xx
> set reso on
>
>I succeed to preview report control toolbar to user and with #bar _mfi_pgset in menu user can change paper format.
>
>I don't know how to provide change field font in some band from within a program?
>
>Thanks in advance.

Once you've given them the MODIFY REPORT access, it's the same as you would build the report. If you want more control or to limit what the user can do, you can come up with your own interface and manipulate the records in the .FRX file like a regular table, just USE yourreport.frx.