C# Variable compatibility with Cobol using Class Type

Hi , Please help on passing value from C# to Cobol using Class Type project. I have for example a declaration :

01 tmp-rec-date.
   05 date-mm pic x(2).
   05 date-dd pic x(2).
   05 date-yy pic x(4).

How can I pass string / structured value from C# to Cobol using that declaration in Cobol. I'm getting "String cannot be converted to Microfocus.COBOL.Program.Reference". What will be the correct type declaration in C#? Please help.

Regards,

jhayvi