The scripting language of TSD allows access to any DLL function from virtually any MetaStock add-on.  To see the details of how to call a function, TSD will list all the functions available in a given DLL, along with its parameters and a sample script line.

No details regarding how to use a specific DLL or its functions can be given.  You must refer to the documentation that came with the addon for instructions on how to use its functions.