Where I'm at the developers have been updated to Excel 2007, but most of the users haven't. I'm building a spreadsheet template (*.xlt) for a user that's gonna need some vba code included, and I'm wondering what issues I'm likely to run into building this in 2007 instead of 2003? I don't have access to a machine with Excel 2003 for testing, and I'm worried this particular project is headed for disaster.
Writing VBA in Excel 2007 for use in Excel 2003
One difference I discovered is that a subroutine must have a different signature to be called from a menu (in Excel 2003) than when called from the ribbon (in Excel 2007). Whatsmore, Excel 2003 doesn't recognise IRibbonControl and throws compile errors.
To work toward cross-version compatability, I use a Conditional Compilation Argument and then check that in pre-processor macros.
#If USINGRIBBON Then Public Sub CallFromRibbon(control As IRibbonControl) #Else Public Sub CallFromRibbon() #End If ' Code here End Sub
This does mean that you have to save one version of your add-in with the USINGRIBBON flag set to false (for Excel2003) and another with the USINGRIBBON flag set to true (for Excel2007), but this is far easier than maintaining two completely separate codebases.
billb2112 is right. There are numerous changes to Excel 2007 over excel 2003 that are not backward compatible. While the language might not have changed, the objects have been updated. Some have had additional properties added, some work differently and some functions in Excel have changed.
You need to be very careful that what you code works in Excel 2003. I would suggest as billb2112 said that you get a virtual machine to not only test in but also to code in. I do all my Excel development for clients who only have 2003 in a 2003 machine. Note that if users have Excel 2002 or 2000 there are even more differences as you go back and you will simply get runtime errors on any code that these older versions don't support.
update unfortunately jeffs answer is not quite correct. while yes the vba language hasn't been updated it is not the same in 2007 as in 2003. as in 2003 its not the same as in 2002 etc. what has happened is extra and additional functions and arguments for functions have been added. for example there are more options in the FIND function in Excel in 2003 than in 2002. thus if you record a macro (the best way to find these problems) in 2003 and then run it in 2002 you will have run time errors relating to the new arguments that simply do not work in the 2002 VBA editor. following the same process for functions that have changed in excel 2007 and then going back to 2003 to test will help you locate these problems. some examples include conditional formatting, colours (themes) and numerous new spreadsheet functions. jon peltier has the best advice from that regard - develop in the oldest possible version that the client /user will use. Virtual PC 2007 is free to download and install. you will just need a licensed copy of XP/Vista and office to install to run in it.