Loop through SET variable and perform task - batch-file

Question

I am trying to figure out how to loop through a list of SET variables and perform a simple script. This is run in batch mode. Any tips on how to adapt the following code so that it loops through the SET dir variable list?
SET YYYY=%date:~10,4%
ECHO Its %YYYY%
SET dir=dir1, dir2, dir3, dir4,...dirN
ECHO %dir%
:: Loop through each SET dir and perform the following.
:: Create a current year dir in remote directory
C:
cd "C:\my\dir\here\%dir%"
if not exist %YYYY% mkdir %YYYY%
:: Copy files from local to remote for each sub directory
E:
cd "E:\FTP\localdrive\%dir%"
XCOPY "E:\FTP\localdrive\%dir%" "C:\my\dir\here\%dir%\%YYYY%" /S /Y
After valuable comments from users, this appears to work but fails to make dirs 2 through 4.
SET YYYY=%date:~10,4%
ECHO Its %YYYY%
SET dir=dir1, dir2, dir3, dir4
FOR /F "tokens=1 delims=," %%a in (%dir%) do (
if not exist %dir md E:\my\dir\here\%dir%
)
Revised to below and still fails - "%%a was unexpected at this time" on what I think was the md E:\my\dir\here\%%a
SET YYYY=%date:~10,4%
ECHO Its %YYYY%
SET dir=dir1, dir2, dir3, dir4
FOR /F "tokens=1 delims=," %%a in (%dir%) do (
md E:\my\dir\here\%%a
)

Answer 1

Just for information, an alternative to the FOR loop method:
#Echo Off
(Set _yyyy=%DATE:~10,4%)
Echo= It's %_yyyy%
(Set _fold=dir1 dir2 dir3 dir4)
Echo= %_fold%
:: Loop through each Set _fold.
Call :Loop %_fold%
Pause
Exit/B
:Loop
:: Copy files from local to remote for each sub directory
If Not Exist "C:\my\dir\here\%1\%_yyyy%\" MD "C:\my\dir\here\%1\%_yyyy%"
RoboCopy "E:\FTP\localdrive\%1" "C:\my\dir\here\%1\%_yyyy%" /S
Shift
If '%1 Equ ' GoTo :EOF
GoTo :Loop

Answer 2

SET dir=dir1, dir2, dir3, dir4,...dirN
for %%a in (%dir%) do (
echo doing my stuff for %%a
)