That should work fine in "Custom Display Rows". There's special substitutions for rendering the original field, but you don't have to use those as in your case you'd just be using raw substitutions so the below should work fine.
Code:
<a href="[company_url]" target="_blank">[company_name]</a>
The below should also work if you need original rendering of company name field.
Code:
<a href="[company_url]" target="_blank">[field_company_name]</a>
Usage of the company name field layout parameters should also work fine as you're doing.
krileon
