Very first hit on Google searching for Format and Indian:-
From a Google search here is a reply by David Richie to the same question in
January
If you have Excel 2002 or later look up bhattext in help.
Otherwise the following format might help you
[>=10000000]##\,##\,##\,##0.00;[>=100000]##\,##\,##0.00;##,##0.00
(This format separates groups for India/Thailand, format valid for
positive numbers up to 99,99,99,999.99 or 999,999,999.99)
in Excel XP see function BhatText as in Thai Bhat currency.
=BAHTTEXT(A37) [Rupees, Rs., Paise, lakhs, crores] ==
an alternative may be to use Control Panel, Regional Settings, Numbers,
digit grouping.
see:
http://www.google.ca/[email protected]&rnum=1