#!/usr/bin/perl

while (<>) {
        print if m!(-?\d*?.?\d+)to(-?\d*?.?\d+)!m;
        print "$1\n$2\n";
        print "$_\n" for ($1 .. $2);
        }


giving the result:

[barry@localhost]$ ./g
4.5to6.8
4.5to6.8
4.5
6
4
5
6

the "4.5" extracts properly but not the "6.8",
it gets truncated to "6"....?