Parse a non-ascii (unicode) number-string as integer in .NET

I have a string containing a number in a non-ascii format e.g. unicode BENGALI DIGIT ONE (U+09E7) : "১"

How do I parse this as an integer in .NET?

Note: I've tried using int.Parse() specifying a bengali culture format with "bn-BD" as the IFormatProvider. Doesn't work.