Can I use an admissions decision as leverage somewhere else?

[socialworkgrad1234]

I just got into a great MSW program and I'm really glad about it, but it isn't my first choice. The school said I need to confirm my enrollment decision by March 7 (I applied for the "priority" round), but I don't expect to hear from my first choice until mid March. Can I call my first choice and tell them my situation? If I say I need to know by March 7, and they are my first choice, could that expedite their decision or increase my chance of admission? I wouldn't want to come off as rude or entitled or have poor etiquette somehow. Has anyone done this or heard of it going well? Thanks!