如果能装载用户的DLL，可以极大的扩展了XML的功能
是否有相关文献，调试手册只说了一些使用的问题
The function loads an additional user DLL to the memory.
Parameter:
dll_name - DLL name
class_name - Name of the function class
Syntax:
dll_name, class_name

Example:

_T"customer"
dll.function The function calls a function from a user DLL. All parameters listed
Parameter:
class_name - Name of the function class
id - Of the function

function calls a function from a user DLL. All parameters listed
after the parameter ID are transferred to the function called.
Parameter:
class_name - Name of the function class
id - Of the function
parameter - 7 - Function parameter (string variables)
Syntax:
class_name, id,
parameter1, parameter2
Example
_T"customer", 290,
_T"par1", _T"par2"