Okay I love this community and especially in this situation this thread. Turns out Brian called a bunch of Zapier experts (anyone he could find a phone number to call!) and left messages with or spoke with them.
So I just called him back not knowing he was the same client from this thread and I got a bit more information from him. I'm going to do a little digging on the capibilities, but I suspect this is going to be a tough nut to crack. The CRM is https://www.reiblackbook.com/ and here's an example form: http://u102909.h.reiblackbook.com/new_zips___arizona/ he does not have the ability to put javascript on that form.
REIBlackBook also offers a CSV import which I got really excited about until the client informed me that they need it to be imported within minutes of acquiring the lead, so a daily batch import will not work for him.
This is a tough one and I suspect it cannot be done without significant effort and significant possibilities for error in data injection etc.
However I did discover that this "CRM" is built in wordpress... huh... the form submits to an empty iframe on the page... I was hoping for a POST url and I could just webhook into that, but I'm not familiar with forms that submit to an on-page iframe.