It works perfectly for me: 
use strict;

my $source = 'VM';
my $COB    = '20080605';

while (<DATA>) {
    if (/^$source.*$COB/) {
        print "Matched $_";
    } ## end if (/^$source.*$COB/)
} ## end while (<DATA>)

__DATA__
VMTKSWPDCN0120080717.TXT
VMTKSWPSLN0120080717.TXT
VMTKSWPDLA0120080717.TXT
CMVMCSHFEN0120080605.TXT
VMTKSWPDLN0120080605.TXT
VMTKSWPTVN0120080605.TXT
VMTKSWPSLN0120080605.TXT
VMTKSWPDLA0120080605.TXT
VMTKSWPTVA0120080605.TXT
VMTKSWPDCN0120080605.TXT
VMTKSWPSLA0120080605.TXT

[download]
Output: 
Matched VMTKSWPDLN0120080605.TXT
Matched VMTKSWPTVN0120080605.TXT
Matched VMTKSWPSLN0120080605.TXT
Matched VMTKSWPDLA0120080605.TXT
Matched VMTKSWPTVA0120080605.TXT
Matched VMTKSWPDCN0120080605.TXT
Matched VMTKSWPSLA0120080605.TXT

[download]
Are you sure that $_ contains the correct string to match?

Note: if you have to match against a huge number of strings, it will be faster to pre-compile the regex-pattern:

my $source = 'VM';
my $COB    = '20080605';
my $regex = qr /^$source.*$COB/;
while (<DATA>) {
    if (/$regex/) {
        print "Matched $_";
    } 
}

[download]

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

In reply to Re: Passing regex inside via a variavble by CountZero
in thread Passing regex inside via a variavble by Anonymous Monk

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