I don't know if this will help, but you can probably use a Windows-configurable bootloader like
GAG. Note that you should make sure that whatever you use won't cause you problems (see MozillaQuest article on Symantec's BootMagic
here).
Ayway, the point is that I don't think* you have to use the default bootloader from your distro.
-David
*but I could be wrong...
edit:
Note that my suggestion of GAG was only because it was the first thing I came across. I have never used it. You can check out
SourceForge for more opensource projects (i.e., bootloaders) that may be of use.