Corion and shmem have both suggested an approach using a split on whitespace. You would need to take precautions if the path can include spaces. This can be done by isolating the path field using three-argument splits from either end of the record.

use strict;
use warnings;

my @records = (
   qq{FRAG 1 1 2000000 0 0 0 0 \\\\172.20.13.49\\backup\\rbgmst02_dd2\
+\stu1\\CPOSTA_1221170039_C1_F1 rbgmst02 65536 0 0 -1 0 *NULL* 1222379
+639 1 65537 0 0 0 0 0 0 0},
   qq{FRAG 1 1 2000000 0 0 0 0 \\\\172.20.13.49\\backup\\rbgmst02_dd2\
+\New Folder\\Space File rbgmst02 65536 0 0 -1 0 *NULL* 1222379639 1 6
+5537 0 0 0 0 0 0 0},
   );

foreach my $record ( @records )
{
    my @leftFields = split m{\s+}, $record, 9;
    my $path = (
       reverse
       map { $_ = reverse }
       split m{\s+}, reverse( $leftFields[ 8 ] ), 18
       )[ 0 ];
    my $basename = ( split m{\\}, $path )[ -1 ];
    print qq{$path\n     $basename\n};
}
[download]

The output,

\\172.20.13.49\backup\rbgmst02_dd2\stu1\CPOSTA_1221170039_C1_F1
     CPOSTA_1221170039_C1_F1
\\172.20.13.49\backup\rbgmst02_dd2\New Folder\Space File
     Space File
[download]

I hope this is of interest.

Cheers,

JohnGG