code: public void setParameter(String name, String namespace, Object value)
    {
  
      VariableStack varstack = getXPathContext().getVarStack();
      QName qname = new QName(namespace, name);
      XObject xobject = XObject.create(value, getXPathContext());
      
      StylesheetRoot sroot = m_stylesheetRoot;
      Vector vars = sroot.getVariablesAndParamsComposed();
      int i = vars.size();
      while (--i >= 0)
      {
        ElemVariable variable = (ElemVariable)vars.elementAt(i);
        if(variable.getXSLToken() == Constants.ELEMNAME_PARAMVARIABLE && 
           variable.getName().equals(qname))
        {
            varstack.setGlobalVariable(i, xobject);
        }
      }
    }
docs: Set a parameter for the templates.
  
  @param name The name of the parameter.
  @param namespace The namespace of the parameter.
  @param value The value object.  This can be any valid Java object
  -- it's up to the processor to provide the proper
  coersion to the object, or simply pass it on for use
  in extensions.