How to rename file with first 32 characters of text file with batch file

How to rename file with first 32 characters of text file with batch file

I would please like someone to help me with this code (shown below). All i
want is the new file name needs to be the first 32 characters of the first
line of the file?
cd c:\test2\test
for /f "delims=" %%i in ('dir /a-d /b *.txt') do (
set nname=
set fname=%%i
for /f "usebackq delims=" %%f in ("%%i") do if not defined nname set
"nname=%%f"
setlocal enabledelayedexpansion
set "nname=!nname:~0,40!"
rename "!fname!" "!nname!"
endlocal
)
Thanks in advance...