VBA stands for Visual Basic for Applications. It's a rich programming language developed by Microsoft that's available inside most MS Office products.

It's original use was for running macros, but advanced users can use this to write software that automatically operates and controls these MS Office products, makes decisions, responds to events, controls other products, sends messages over the internet, and more.

Unfortunately, I'm not a Mac user, and so I can only offer to build spreadsheets for MS Office products running on Windows.

Sometimes, simple solutions developed for Windows will also work on Mac, but I cannot warrant this.

Projects vary considerably in the time and effort required to build them, ranging from a few hours to a few weeks. A few days to a week is fairly typical for a simple, single-user development.

I only charge for the time I actually spend on your project, which includes time spent designing and creating spreadsheets, developing and testing software, installation, preparing documentation, support, training, etc plus meetings, long telephone calls or emails.

I'm not a major software house with expensive overheads and high day rates. My hourly rate is admittedly more than my gardener charges, but less than my car mechanic or central heating engineer charge.

Charging annual support or licence fees is often a way software businesses generate easy revenue. In my experience, once the software has settled in, it normally continues to work without problems.

So I normally don't charge annual licence or support fees, if what I build is just intended to be used by your business. If you do need my help, just get in touch, and I'll try to help as soon as I can, and I'll charge my time at my usual hourly rates.

Microsoft continuously adds new features to Excel, making things that were once quite difficult to do, much easier to achieve in later versions, and so there's a benefit to be had in upgrading every now and again.

Of course sometimes as a user you have no choice but to stay working on a very old platform - perhaps you have some software that is vital to your business that only works on (say) Windows Vista.

Well the semi-good news is that it's still often possible to create solutions that run on older versions, but it is likely to take more time and effort to achieve, you'll probably have to help with the testing and debugging, and the end-result may be less satisfactory than you'd have achieved with a later version.

So if you have a version of Excel that's (say) 10 years old, and you're contemplating spending money on a non-trivial development, it will likely be cost-effective to upgrade first.