SET MYVAR="Hello World"
ECHO %MYVAR%

@echo off
rem Paths to combine
set DIRECTORY="C:Directory with spaces"
set FILENAME="sub directoryfilename.txt"
echo %DIRECTORY%
echo %FILENAME%

rem This is just to illustrate how the = operator works
set DIR_WITHOUT_SPACES=%DIRECTORY:"=%
echo %DIR_WITHOUT_SPACES%

rem Combine two paths
set COMBINED="%DIRECTORY:"=%%FILENAME:"=%"
echo %COMBINED%