Looking for Unicode Plain Text Math parser/converter

[software at ogee-group.com]

Hello,

I am new to this list.  I am looking for a parser/converter in C++/C#  
to interpret a Unicode Plain Text Math expression (see UTN 28 or UTR  
25) and convert it to MathML.

Example expression: \sum_(i=1)^n \naryand x_i

Any help would be greatly appreciated

Thank you,

s.