You need to configure your Red Had Linux install to act as a samba (SMB) server. To do this you need to install the samba rpm and configure it to share the folder to the network.
to see if samba is installed, type:
$ rpm -qa samba
to install samba from your cdrom, type:
# rpm -ivh /mnt/cdrom/RedHat/RPMS/<name of samba rpm>.rpm
then you need to configure the workgroup name, the share and add a samba user that is also the user of the XP box.
# vi /etc/samba/smb.conf
and add a share at the bottom of the file:
path = /path/to/share
read only = no
save the file.
now add a user to samba (the same user must have a Linux account)
# smbpasswd -a <user>
now start the samba server
# /etc/init.d/samba start
now you should be working ok. the only thing that may block the XP machine connecting is if you have a firewall running on the RH9 box.