An excel macro user is very useful in a company. Process improvements that save time translate into cost savings for the firm. But each working group/department only needs 1 excel expert to set up all the macros and troubleshoot, while the rest just learn how to use the macro. You become a pseudo public good, as others free-ride on your expertise.

That said, proficiency in excel is always useful as it is a "free" software that is widely available and used in most companies. If you specialize in industry specific software like SAP or Bloomberg, then its not as transferrable.

I think Powerpoint (or some other presentation-creation software) is another wonderful skillset to develop.