First of all, I already have MSDN July 2000 version installed, and so when F1 is pressed, VS98 doesn't ask for any MSDN folder (which is as it should be) and opens the July 2000 version. So ur solution is futile.
Secondly, installing MSDN Oct2005 in another folder (non-default folder, that is) will also not work as its required to be linked with the VStudio IDE somehow, which is possible with the help of the 'MSDN Collection settings' but unfortunately that is also not working.
Thanks for ur reply though.