Approach to convert number into text (SSRS report body to footer)

Hi everyone! 

I'm working on  SSRS report that is very similar to CashBook_LV.  But in my customization, I need to  display in words number of rows in report body tablix.

For now, my approach is to write DataMethod  C# code  in the SSRS report. But, I want to use my x++ classes and static methods to achieve my goal.

Because, in the near future we will migrate from ax2012 to ax7, and I need reduce  concomitant work with this.

Thanks for answers.