AppLogic.ProcessManager pm = new AppLogic.ProcessManager(); // Синглетон
pm.Repository = new AppLogic.XmlRepository(@"..\Xml\Repository"); // Репозиторий, где хранятся описания всех команд
AppLogic.Command cmd = pm.CreateCommand("PrintExcelReport"); // Получения экземпляра команды через Reflection

// Инициализация параметров
cmd.Param("ConnectionString").Value = @"data source=WMS\TEST;user id=sa;Password=1111;initial catalog=DB";
cmd.Param("TemplateFileName").Value = @"..\ReportDocuments\ActDiffrence.xml";
cmd.Param("SQL").Value = "exec OR_ActDiff_Print '7732'";

// И собственно выполнение
cmd.Execute(null, "");

<?xml version="1.0" encoding="windows-1251" ?>
<PrintExcelReport Caption="Отчет Excel">
  <var name="ErrorMessage" />
  <var name="Connection" />
  <var name="ReportData" />
  <var name="ReportFileName" />
  <param name="ConnectionString" />
  <param name="TemplateFileName" />
  <param name="SQL" />
  <command name="TryCatch" caption="Обработка ошибок">
    <param name="ErrorMessage" output="">$ErrorMessage</param>
    <try>
      <command name="CreateSQLConnection" caption="Соединение с базой">
        <param name="ConnectionString">$ConnectionString</param>
        <param name="Connection" output="">$Connection</param>
      </command>
      <command name="SQLQueryXml" caption="Формирование данных">
        <param name="Connection">$Connection</param>
        <param name="SQL">$SQL</param>
        <param name="ParamDefs"></param>
        <param name="ParamValues"></param>
        <param name="XmlDocument">$ReportData</param>
      </command>
      <command name="ExcelReport" caption="Отчет Excel">
        <param name="ReportFileName">$ReportFileName</param>
        <param name="ReportCaption">Список погрузки</param>
        <param name="TemplateFileName">$TemplateFileName</param>
        <param name="ReportData">$ReportData</param>
      </command>
      <command name="OpenShell">
        <param name="Application">Excel.exe</param>
        <param name="Arguments">$ReportFileName</param>
      </command>
    </try>
    <catch>
      <command name="ShowMessage">
        <param name="Message">$ErrorMessage</param>
      </command>
    </catch>  
  </command>
</PrintExcelReport>