[windows] Decoding base64 in batch

I am trying to make an installer using batch. Of course, an installer needs to consist of files that will be installed, so I'm thinking of encoding the files in base64, and simply decode them and write them to their destination.

Of course, my work would be very easy if Windows had something like the base64 tool that Linux boxes contain. However, since it's simply not there, is there any way to decode base64 content completely using batch files? And how would I accomplish this?

Any help is appreciated.

(It's just an experiment, so I'm not worried about inefficiency and the like.)

Here's a batch file, called base64encode.bat, that encodes base64.

@echo off
if not "%1" == "" goto :arg1exists
echo usage: base64encode input-file [output-file]
goto :eof
:arg1exists
set base64out=%2
if "%base64out%" == "" set base64out=con 
(
  set base64tmp=base64.tmp
  certutil -encode "%1" %base64tmp% > nul
  findstr /v /c:- %base64tmp%
  erase %base64tmp%
) > %base64out%