What's wrong is the way you are entering the file name. Double quotes allow interpretation of what is between them:
I.e. step 1:
print out the name of the file:

 perl -e ' use P;
my $filelist="C:\Users\cign\Desktop\printFile.txt";
P "opening file: %s", $filelist;
'
opening file: C:SERS    GNDESKTOPPRINTFILE.TXT
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Is that the file you wanted to open? Prolly not.
step 2, at least turn on warning and try to use strict - they detect alot (though not all) of problems -- in this case they would have given you a hint:

perl -we 'use strict; use P;
my $filelist="C:\Users\cign\Desktop\printFile.txt";
P "opening file: %s", $filelist;'
Unrecognized escape \D passed through at -e line 2.
Unrecognized escape \p passed through at -e line 2.
opening file: C:SERS    GNDESKTOPPRINTFILE.TXT
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use single quotes to define a literal, or put another backslash \ before each \, or use the 'q{...}' operator to really set it off that emphasizes it has to be taken literally (and doesn't interfere with my using single quotes in a 1 line program I typed in on the command line! ;-)

 perl -we 'use strict; use P;
my $filelist=q{C:\Users\cign\Desktop\printFile.txt};
P "opening file: %s", $filelist;'
opening file: C:\Users\cign\Desktop\printFile.txt

##
#alternate ways   
##

> perl -we 'use strict; use P;     
my $filelist='\''C:\Users\cign\Desktop\printFile.txt'\'';
P "opening file: %s", $filelist;'
opening file: C:\Users\cign\Desktop\printFile.txt

##

> perl -we 'use strict; use P;
my $filelist="C:\\Users\\cign\\Desktop\\printFile.txt";   
P "opening file: %s", $filelist;'
opening file: C:\Users\cign\Desktop\printFile.txt

###

## my favorite (in a file)...

#! perl/bin/perl.exe
use strict; use P;
my $filelist="C:/Users/../tmp/../Perl64/printFile.txt";
P "opening file: %s", $filelist;
open (test, ">", $filelist) or die "didn't work";
print test "Hello World!\n";
close test;
C:\Perl64>perl test.pl
opening file: C:/Users/../tmp/../Perl64/printFile.txt

C:\Perl64>type printFile.txt
Hello World!
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Forward slash works in alot of places on Windows cuz the underlying 'NT' OS accepts it.