how can we add display method to the SSRS Report

I have problem with display method. I created method convert number to string Class and use display method, which i create in Tmptable, for call method convert. I use Datasource type as Report data provider. I don’t know step add display method to ssrs report. Please help me tell this step if you have a time.

Thank you.

Pichamon

Oh, sorry I forgot tell something. I don’t have form. in this Class created for Report. (SalesConfirmDP)