Are you able to use other languages instead of VB for Excel macros?

Yes it is possible to write excel macros in Python via pyxll

On a side note, you can even edit the existing macros in Python:

https://stackoverflow.com/questions/9913603/is-it-possible-create-edit-an-excel-macro-from-python

Another option is C# using .NET. Check out this link:

http://excel-dna.net/

I've not used it much, but it might be worth a try.

It is important to note, that since exactly all Excel automation capabilities available to VBA are in fact served through the COM interface, you can use any language, which supports Windows COM (ActiveX) objects. It roughly translates to almost every modern programming language on the Planet. I personally successfully used Excel from Wolfram Research Mathematica and pure C++. If you don't have specialized library for handling Excel object hierarchy (like the one that I presume exists for Python), it may not be that nice to use as with native VB.

Visual Basic 6 (and Visual Basic for Applications) were designed with compliance with COM architecture in mind. It means, that most data types defined for COM are native for Excel and they don't need to be transformed upon each call. So I'll suspect, that handling Excel from within VBA is the most efficient.