convert the hexadecimal GUID to a string GUID

[Chris]

I have following objectguid as hex guid:
D4 16 D8 5C D0 D6 EC 47 91 89 13 B8 36 74 F3 C1.

How to convert it into string GUID format as
xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

I found an article (MS KB 325648) to convert string GUID to Hex string form.
But in my case I need to reverse.

Thanks.