To start with, there is no such thing as Hindi font or English font! It's all Unicode, and there are fonts supporting some sub-sets of code points, scripts. There is even no such script as Hindi, there is Devanagari script (
http://en.wikipedia.org/wiki/Devanagari[
^]) which is used in a number of Indian languages.
You just need a font which support Devanagari. Use standard application "Character Map" bundled with all versions of Windows. One font which certainly support Devanagari and ASCII (if Mangal does not, what's the use of such font?) is "Arial Unicode MS".
—SA