There are some solutions out there. Unfortunately most require some modifications.
http://www.biagmbh.com/cgi-local/reloc/reloc.cgi?goto=katalog/pdfs/74/7407.HTM
http://www.lindy.co.uk/mains-power-lead-with-locking-iec-connector-uk-3-pin-plug-2m/30138.html
http://www.biagmbh.com/cgi-local/reloc/reloc.cgi?goto=katalog/pdfs/74/7407.HTM
http://www.lindy.co.uk/mains-power-lead-with-locking-iec-connector-uk-3-pin-plug-2m/30138.html