No need for an application, but you need to make sure that fat32 support is compiled into your kernel.
Once you're sure of that, just edit /etc/fstab to include an entry for it. At the end of the file, append the following line:
/dev/hda4 /mnt/dos vfat defaults 0 0
This mounts the 4th IDE partition of yours ( /dev/hda4 ) on /mnt/dos directory. Make sure you have a mount-point (mkdir /mnt/dos) and verify which partition holds your FAT32 system - fstab will give you that information.