I always copy those files to a subfolder from the location where I run chroot. So: Copy both files over to /home/user/archlinux either through your USB or by terminal. After that, chroot into archlinux and copy those files to the appropriate places, id est set-focus goes to usr/bin/ and the other one goes to /sbin/ While still chrooted you should be able to chmod +x both these files.
deny_winarto: Just make a .desktop file in /usr/share/applications/hildon with the command you use to run openoffice in the "EXEC=" line.