This command is used to declare a command implemented in an external ScriptBasic library. Do NOT use this command to invoke a function from an external DLL that was not specifically written for ScriptBasic. When you include module BASIC files that contain DECLARE COMMAND lines, you can call the functions declared this way as they were entirely written in BASIC. You use/write a DECLARE COMMAND command if you developed an external module for ScriptBasic programs in C.