Marie, you may want to pick up an Anatek "Pocket Pedal"[long discontinued]..It has several functions made assignable thru a midi connection, for both a sustain pedal and an EV5 expression pedal..

Marie if you can't find one..I can let you borrow mine...Email me..
http://cgi.ebay.co.uk/Anatek-Pocket-Peda...8QQcmdZViewItem