zip up each .TXT file individually, deleting the source file and setting the name of each .ZIP file to the basename of the .TXT file
NOTE: Under DOS: the “dir /b” switch returns bare filenames in all caps).
echo @echo off >zipup.bat dir /b *.txt | sed "s/^\(.*\)\.TXT/pkzip -mo \1 \1.TXT/" >> zipup.bat