Edit Parameters data type through programatically

Hi , I am working on to edit / modify parameters data type in SQL command programmatically using c#? Can please anybody let me know how to edit parameters data type which are there in the command through code. currently I can find Command like this foreach (CrystalDecisions.ReportAppServer.DataDefModel.Table tmpTbl in reportClientDocMtf.DatabaseController.Database.Tables)                 { if (tmpTbl is CommandTable)                         {                             CommandTable cmdTbl = (CommandTable)tmpTbl; } }