Cs after mba-hr? plz advise and suggest?

I have done MBA-HR from a fairly reputed institute, but to have an additional degree i am thinking to register for CS exam. Plz suggest on same as it should not lessen the importance of MBA-HR in future, although i will be working as an HR professional and studying for the same simultaneously.As MBA in HR will not take me long if someday i aspire to be the CEO OR some other big position in any Company? Plz help me on this? I need guidance.
Liza