If you want to change 45-48 into 45,46,47,48 you can do this.

use strict;
use warnings;


while ( <DATA> )
{
        if ( m/^(\d+)-(\d+)$/ )
        {
                for my $value ( $1 .. $2 )
                {
                        print "$value,";
                }
        }
}

__DATA__
45-48
88-99
102-124
[download]

Output
45,46,47,48,88,89,90,91,92,93,94,95,96,97,98,99,102,103,104,105,106,10
+7,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124
+,
[download]