How to approach alum whose company has an open position I want?

Hi, I'm currently job searching and there are a few instances where I see a posting for an open position and I have a school alum working at the company with the open position.

**So question is, how do I approach the alum to clearly but not too directly tell them "I want to apply for this position, can you flag my application"? Should I ask for a phone call, so that they get to know me better and will vouch for me personally? ** **

( I don't want to reach out with a message that says "I want to learn about the field..." because 1) it will look very fake and insincere when I finally reveal that I saw a job posting at their firm and 2) I don't have the turnaround time for all this, since the position might be filled while we chit chat.)

**What should I write in my email as the purpose for a phone call? **It doesn't seem very relevant to say I want to learn about their experience, since I will be applying for an analyst position and they're a principle. And if I am clear about my purpose of wanting them to flag my application, then there seems to be no point of a phone call, they might simply respond they'll flag it to recruiting, which they might or might not actually do.

Please advise!