weeellllll - the first point is that one doesn't have the same data in two places in a "properly" normalized relational database....as I scold you and shake my finger.... so that's really the issue here....
if those fields are indeed always identical data - abandon the field in the helpdesk table.
if those fields are not always identical data - then have both fields in the helpdesk form via either a join in your underlying record source for that form or via a subform technique.
assuming I get rid of the field in my helpdesk table, how would I show the phone number coming from the hospital_users table? Right now I am using a after_update event on my callers name that adds the phone number to the helpdesk table from my query.