The regulations are here 46 page pdf...
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADP_2006.pdf
Your installer will place the pull cord switch wherever you want it and charge you accordingly - unless - the regulations specify otherwise. To go against the regulations will hurt the installer and possibly you.
It would be foolish and potentially dangerous to have the pull cord in another place.
Peccavi
April 2010