CRC32 - Need to pull the CRC from a *.dll

Hi,
Nobody will probably be able to help with this, but here it goes anyway.
If I have a .dll in the root of any directory, for example on a system running US Office C:\\Program Files\Common Files\Microsoft Shared\Proof\Msspell3.dll
and Msspell3.dll being the target; I want to find the CRC32 of this file?? how would I approach this problem with regard to the actual code to pull the CRC32 from the file?

I am aware of the following Construtors and methods, but I do not know how to implement them.

CRC32()

getValue() Returns CRC-32 value.
reset() Resets CRC-32 to initial value.
update(byte[]) Updates CRC-32 with specified array of bytes.
update(byte[], int, int) Updates CRC-32 with specified array of bytes.
update(int) Updates CRC-32 with specified byte.


If anyone could help I would much appreciate it..
Thanks in advance..