How to escape variables with parentheses inside if-clause in a batch file?

Question

Running this batch file

@echo off
set a=some value with (parentheses) inside
if 1 == 1 (
    set PATH=%a%
)

gives inside was unexpect

Answer 1

Brackets and variables are always a pain to mix. Use a subroutine instead.

@Echo Off
Set a=some value with (parentheses) inside
If 1 == 1 Call :SetPath
Echo %Path%
Exit /B

:SetPath
Set "Path=%a%"
SetX "Path" "%a%"
Exit /B

I set the variable twice, once using Set for the current shell session, and one using SetX to set it system-wide for future shell sessions. Remove either if they're unneeded.