c:\@Work\Perl\monks>echo Bleach='^(GUI_|AA_|myMainScript)'
'AA_' is not recognized as an internal or external command,
operable program or batch file.

c:\@Work\Perl\monks>echo "Bleach='^(GUI_|AA_|myMainScript)'"
"Bleach='^(GUI_|AA_|myMainScript)'"

c:\@Work\Perl\monks>perl -le "print qq{>>$ARGV[0]<<};"  Bleach='^(GUI_|AA_|myMainScript)'
'AA_' is not recognized as an internal or external command,
operable program or batch file.

c:\@Work\Perl\monks>perl -le "print qq{>>$ARGV[0]<<};"  "Bleach='^(GUI_|AA_|myMainScript)'"
>>Bleach='^(GUI_|AA_|myMainScript)'<<