Should I build an Excel 2000/2003 version?

As I build Time-Creator, I'm wondering if I should make the software work on Excel 2000/2003. The first requirement is that you need a copy of the software and I have one on an old laptop.

The second is will there be enough customers that use this version to make it worthwhile?  I've started on making my program compatible but then realized it's taking away from my main focus.  I could always come back to it.

As I'm working on it I'm finding a number of compatibility issues with the VBA code I'm writing using Excel 2010.  The biggest ones are:

•  Ribbon isn't available in the previous versions
• Callbacks don't work 
• Sort command issues
• New bugs introduced by changing code to support Excel 2000

I've met my first goal to get out a version of Time-Creator that user's can download. My second goal is a bug free version and third is a version that's easier to use.  The Excel 2000/2003 version will have to wait unless I hear back from lots of users who want it.

Though, it's very tempting as I've spent around 5 hours already on this I may try to get out a version.

What version of Excel do you use? Should I build an Excel 2000 compatible version

Securing an Excel Spreadsheet

Security is an issue if you're a software developer.

There is always a trade-off between too much security and too little. Too much and you annoy your users and too little and people have a free-for-all with your product. When it comes to securing Excel software or any software someone can always reverse engineer what you've done.

 So the first thing to do is to add a password to your work. Go to the "Review" ribbon and select "Protect Workbook". Give it a nice long password to make it harder to crack. The second thing you can do is obfuscate the code. This means converting it from something that's easy to understand to something that's not. I worked on a tool to do this but never finished it.

 Searching on Google brings up 192,000 entries so someone has also thought about this.
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Now you need to secure your VBA code by going to Tools - VBA Project Properties, click the Protection Tab and then click the "Lock project for viewing" and enter and confirm your password.

Setting the Tooltip on the Excel Ribbon

I have so much to do with this project. Currently trying to get the Tooltip to work from the Ribbon in Excel.

I found something from https://groups.google.com/forum/?fromgroups=#!topic/exceldna/7uMLPOrRJqw which lists the following:

The other parts of the tooltip popup are customised with "screentip" 
and "supertip": 
   <button .... screentip="This is the screentip " supertip="This is the supertip " /> 
and you can do a getSupertip callback. 

I'm using a tool called "Custom UI Editor for Microsoft Office" and if you're modifying the Ribbon it is a must have.