Bit Fields

[Matt Minnis]

Is there a way to dynamically define bit fields in a integer?

I know how to define them in code, but how can it be done for purposes of 
reading in a file that would be easier to deal with if there was a way to 
do this.

Basically, read in a file describing internal registers of a micro 
controller of some sort, and have the bit fields to designate the different 
functions of some of the bits.

I know this can be done via a mask, but I would like to know if this is 
possible?

Thanks,

Matt Minnis