!1026:s/original/replacement/
Here is an absolutely incredible online tutorial about history bang recall:
http://www.softpanorama.org/Scripting/Shellorama/bash_command_history_reuse.shtml
Here is a much smaller page on the subject, it might have something extra to add:
http://pic.dhe.ibm.com/infocenter/aix/v6r1/index.jsp?topic=%2Fcom.ibm.aix.baseadmn%2Fdoc%2Fbaseadmndita%2Fc_hist_sub.htm