Just to make a minor point (plus get my first post in for 2003! ;)), the original poster's data has semicolons as the separating character instead of the default comma, which can easily be specified in Text::CSV_XS's sep_char attribute in the new() method. Hope I'm not doing anyone's homework: 
#!/usr/bin/perl -w

use strict;
use Text::CSV_XS;

my ( $csv, $xml );

$csv = Text::CSV_XS->new( {
                            'sep_char'    => ';'
        } );

$xml = '';

while( <DATA> ) {
    chomp;
    if ( $csv->parse( $_ ) ) {
        my ( $line, $n, @fields, $field );
        $line = '<row>';
        $n = 1;
        @fields = $csv->fields();
        foreach $field ( @fields ) {
            $line .= "<col$n>$field</col$n>";
            $n++;
        }
        $xml .= $line . "</row>\n";

    } else {
        print "parse() failed on this line: " . $csv->error_input() . 
+"\n";
        # die?
    }
}

print $xml;

__DATA__
a;b;c;d;e
f;g;h;i
j;k
l
m;n;o

[download]
Output: 
$ ./main.pl
<row><col1>a</col1><col2>b</col2><col3>c</col3><col4>d</col4><col5>e</col5></row>
<row><col1>f</col1><col2>g</col2><col3>h</col3><col4>i</col4></row>
<row><col1>j</col1><col2>k</col2></row>
<row><col1>l</col1></row>
<row><col1>m</col1><col2>n</col2><col3>o</col3></row>
There's probably an XML package out there should your required output become more complex or you want to guarantee that you are using a standardized and optimized solution.

Peace,

Purdy

In reply to Minor addition by Purdy
in thread newbie regex question: substituting repeating occurences for different replacements by RuyLopez

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