How to properly quote something in a Batch file?

What is the proper way to quote a variable in a batch file?

I've found that something like "%~dp0" doesn't work because it turns out to be something like "C:\Windows\", which in turn gets interpreted as having an escaped quote at the end.

Oh and of course there's always problems with embedded quo开发者_StackOverflowtes -- any way to escape those too?

You are mixing a bit the different quote/escape problems here.
In batch itself there are different rules for quotes and escapes than for reg.

In batch a caret escapes the next character, but only outside of quotes (there is only one exception for escaping an exclamation mark inside of quotes).

reg.exe uses the \ to escape the next character, EDIT: but it seems that it only escapes a quote character.
To embedd a single quote it's easier to use two quotes.
Only a backslash at the end of the content is a problem, as it escapes the last quote.

Reg Add HKCU\Temp /d "One""two\\" /t REG_SZ

Adds One"two\

Which variable are you trying to quote ? If you have defined the variables in the environment/system varaibles, then you can quote it as
%variable_name%.
For example if you need to quote the 'path' variable, then %path% is the right way

If you want to pass something with spaces into a variable use ` ( top left of the keyboard ), this should also deal with embedded quotes. If you're passing a variable with spaces into another batch use double quotes.