If you mean to set a status of a Test Step to "Omitted", yes you can but only after you added "Omitted" as an Execution Status in the Tools / Customize area. Usually project admins are the ones able to do this.
Just a note, in my company, we have a set of standand Execution Status so we don't usually add custom or ad hoc statuses without releasing it as a new set to standards. Not sure if this is how it's done in yours.