Excel 2003 to Excel 2007
 

Hi,

From my application I generate the .xls workbooks (with macros) filled with
data. I use standard .xlt files (office 2003 template files with macro),
stored centrally in a network share.
1. create a new instance
2. fill data
3. save it to the disk and
4. present it to the user.

Now I have users in 2003 and in 2007. Given that the templates are stored
centrally I need to support both version of the office.

At present if I generate the workbook using my .xlt files,then the user is
informed that "To save a file with these features,click No, and then choose a
macro-enabled file type in the File Type List".

Also the users using either of the two versions of the office can manipulate
or change the same system generated workbook and store it back to the network
share drive.

Questions:
1. What changes I will have to make to support both versions of Excel?
2. Is there a way where the office 2007 can save a macro enabled workbook
without the new extension?

Thanks
Manish Agarwal