This is not an appropriate sentence. "请问" is just a part of a question, similar to "I would like to ask". It is possible that someone would say it alone for catching the attention of another person, but that would mean there's a question to finish. By no means an exclamation mark could have been used here to end it like a phrase on its own. Abbreviation mark（……）should be used.
Don't use this as an equivalent of Excuse me. Say rather 不好意思.