I got the error at the following code of my asp file:
ax_FromWoID = lo_Conn.ACNS022V_ACAS022.FROM-WO-ID
It seems that the VBScript handled WO as a separate varible, and treated it as subtraction. But, it should be FROM-WO-ID is a element/attribute of a dll.
Therefore, how can do what I want? Just pass the attribute value from the dll to the variable ax_FromWoID without re-design and compile the dll.