modules and kernel elements

[Ben Ransom]

I want to add a module (ntfs read) to a system running redhat enterprise WS 
with kernel 2.4.21-20.

Going to the kernel src directory (same version as what is running) and 
doing a `make oldconfig`  ...will that generate a .config file that would 
represent the same kernel parameters and modules as a system originally 
installed from CD and patched using up2date?   What does "oldconfig" read 
to determine to define in .config?
Thanks,
-Ben