when there is no application just submitting of resume. This is for a seasonal job, walk-in interview. You know someone who works at the company and they are willing to recommend you or have his name on your application whereever needed.
I would just be up front and mention it. I'm sure these kind of recommendations happen quite often.
We have "summer help' and seasonal help at work who are college students on break, and word of mouth is usually how they get the job.
Just say "so and so, recommend me, I'm _____ please to meet you." Just say it in a casual way. No need to tightned you butt hole over this.
One of my friends recommended me to her boss and her boss ended up calling me in for an interview. That's another way of going about it.