How can you change file format from .xsl to .xml programmatically

[Shimo]

Can someone tell me whether it is possible to change an Excel spreadsheet
from a .xsl format to an .xml format programmatically without having Excel
open a window. I would like this to happen in the background. It would be
ok if Excel was opened but I just do not want a window visible to the user.

Thanks,
Lloyd

 

[Shimo]

I would like to clarify my question. I would like the data of an Excel
spreadsheet that is stored in .xsl format to be converted to data in .xml
format. The reason I need to do this is that I want to be able to access the
spreadsheet data in order to validate and manipulate the data. Having the
data in xml format allows me to easily do this.