Batch File 4 Mass Imageconversion in Windows and Portable (or installed) Imagemagick
I prefer the portable version from https://imagemagick.org/script/download.php
Download the correct ICC File from http://www.eci.org/de/downloads
and copy it next to the batchfile
Fix your Paths in identifyprog and magickprog
choose your Original Path
and final SEARCHTEXT and REPLACETEXT
and correct "eciCMYK.icc" in "%magickprog%" call.
Call Convert2Cmyk.bat from commandline, or doublecklick.
Happy CMYK conversion, or whatever you want from magick