Over the years, Excel has added a lot of functionality to VBA, and even expanded old functions which have been there all along (adding new arguments to old functions). Sometimes, there might not be many changes in VBA from one upgrade to another, but over 17 years, there has been a LOT of changes. So I would fully expect that only your macro was doing something super simple, that the code you wrote in Excel 2014 would not work in Excel 1997.
As a general rule, when programming VBA, you usually want to program the code in the lowest version of Excel that any user may be using (so if you have users using 2003, 2007, and 2010, you would want to program using 2003, if possible). Most code written in an older version will work in a newer version, but not the other way around. Over the years Microsoft has added a lot of functionality, and they usually do not take away old stuff (though they did take away a few things in jumping from Excel 2003 to Excel 2007).
So, if you want your code to work in Excel 97, you may need to rewrite/recreate your code using Excel 97.