This is especially the case with mathematicians and erudite scholars during research.
Though there are alternatives, like adobe fonts and so forth, but you cannot expect yourselves to be blessed with such software on every machine you sit on, So you'll need something more mobile, something that you can rely on.
Here's your solution, The website
Is one of the most useful solution to such problems.
It is basically an internet application for copying and pasting characters that does not comes with the computer’s typefaces, to be pasted into emails, tweets, text documents, forums etc.
The website also allows you to create your own set of characters, Though you will have to sign-up with the website which is not a herculean task altogether.
According to the about page of the website, Copy Paste Character was developed in Stockholm, Sweden, by Konst; Teknik; Martin.
Here is a simple Flowchart about, how to operate the website.
Here is a video depicting the website,
This was all about