Thank you Dave.
I managed to solve it so I thought I'll share it here.
For subscripts:
Character Map - > Arial Unicode MS font -> Check Advanced View -> Group by Unicode Subrange -> Super/Subscript
For macron its a little tricky:
Character Map - > Tahoma font -> Check Advanced View -> Group by Unicode Subrange ->Combining Diacritical Marks
Type the character (e.g. y) and double click on "Combining Macron".
Glad everything works!