LinkedIn hResume modification

I apologize, I’m learning this php as I go. Here’s what I want to do.

I want to have a link that passes an url as an argument to my LinkedIn hResume page. Then use that argument in the shortcode, to display the correct LinkedIn data.

Here’s the link code:
$contact .= '<tr><td>' . __('Resume', $this->pid) .': </td><td><a href="https://jeffwithag.com/geoff/linkedin/?linkedin_url='. $resume. '">'. substr($resume, 7) . "</a></td></tr>\n";

which results in this url:
https://jeffwithag.com/geoff/linkedin/?linkedin_url=https://www.linkedin.com/in/geoffbuffett

First, Is my link above fine? Or should it have single or double quotes around the following?
https://www.linkedin.com/in/geoffbuffett

If so, how should I modify the above link code to accomplish that?

Second, my LinkedIn hResume page contains the following:
[lnhr url="https://www.linkedin.com/in/geoffbuffett" caching="on"]

Can I insert an argument(ie: $linkedin_url) inside the shortcode? In other words, can I replace
url="https://www.linkedin.com/in/geoffbuffett"
with
url=$linkedin_url

Or do I need to dive behind the scenes and try to figure out where to set ‘url’ in that code?

Just looking for a little guidance before I attempt it myself, to help me avoid going down a couple of dead ends.

Thanks,
Geoff