Yes, of course it is possible.
What I would do, if I were you, would be to use the windows bootloader with grub here, that way you do not have to change much hardware-wize ...
First, find out what your drive is called with fedora/windows98 ... I guess it is hdb - but there is no way I could know ;-) - it could also be sdc.
to find out, boot into fedora and type
check to see which drive is mounted as /boot, if there is non, check wich drive is mounted as /
dd if=/dev/hdb1 of=/path/to/windows98/partition/bootsec.lnx bs=512 count=1
(make sure you replace hdb with whatever you find)
you take the /path/to/windows98/partition/bootsec.lnx file and put it onto your c drive in windows xp, you should be able to access the windows98 partition from within xp.
In windows xp, open cmd.exe and type
attrib -R -S -H C:\boot.ini
In notepad open c:\boot.ini and you add a line like the following:
c:\bootsec.lnx="Linux and Windows 98"
save, once that is done, go back to cmd.exe
attrib +R +S +H C:\boot.ini
attrib +R +S +H c:\bootsec.lnx