Code page for data in Excel spreadsheets

[Kal]

Does anyone know what code page Excel uses to store the
data in the spreadsheet? Is it the OS code page? is it
unicode?

I have this automation client application that reads data
from excel spreadsheets. I am trying to check to see if i
need to work about conversion from one code page to
another if the data in the spreadsheets is stored in a
different code page than the OS.

any idea?

Thanks

Kal
(e-mail address removed)