Is there something like Command Substitution in Windows CLI?

Try this:

echo. ===== %time% =====

I know this may not be what you want, because you mentioned command substitution... So this may be it:

for /f "usebackq tokens=*" %i in (`date/t&time/t`) do echo.  ===== %i =====

For more hints about the usage of usebackq try this command:

for /?

In Windows the '( )' operator has a similar behavior as the Bash command substitution.

This Linux script:

my_linux_variable=$(ls)
my_alternate_linux_variable=`ls`

echo $my_linux_command=$(ls)
echo $my_alternate_linux_command=`ls`

gives a similar result as Windows PowerShell:

$my_windowsPS_variable = (dir)

$my_windowsPS_variable

and as Windows CMD:

set my_windowsCMD_variable=(dir)
%my_windowsCMD_variable%