Any way to imply the wildcard for an autocomplete field


We have a number of forms with fields that bring a contact's user id in from the contact table and we've set most of them to autocomplete.  This works as expected, so if you start to enter the name the way it appears in the contact file, after the third charater it will start to present a list of user ids that start with the value you start to type.  If you don't know exactly how the user's id is entered in the contact file you can type the asterisk (*), then start typing something you think is part of the user's id and it will also work as expected and start to present a list of values that contain what you type.  What we want is for the asterisk (*) to always be implied without our users having to type it.  Has anyone out there successfully configured something like this or have any thoughts on how I might get it to work?