Open Firefox twice (with same profile)

There are tons of resources that tell how to run several instances of Firefox in parrallel. I can't find *any* that tells me how to configure a command (on a command line, start menu item, or panel button) so that: - the first click opens Firefox with a predetermined profile *New Window" in Firefox, except triggered from a command line. To be explicit, I do not want to involve other profiles. My motivation is that I have lots of desktops and lots of browser windows, and often finding that one window for the profile I want is a lot harder than to just click a button that is always going to be in the same place - on the panel. For the first bullet, I currently use the command "firefox --no-remote -P "thisprofile" %u" and it has always worked as intended. However, for the second bullet, I invariably get the error *"Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system"*. **Clarification:** I have two panel buttons that start separate Firefox profiles. These use "firefox --no-remote -P "ThisOrThatProfile" %u". If I omit any other parameters and just supply "--new-window", it correctly starts new windows *of the default profile* (whether that profile is already running or not). The thing is, I cannot figure out how to start new windows *for specific (non-default) profiles*.