Implementing New User Functions in Microsoft Windows

You can implement new user functions in sqrext.dll or any other extension .dll. All of the extension .dlls must have the InitSQRExtension() function exported. If you implement user functions in sqrext.dll, you should rebuild the .dll by using the supplied make file, sqrext.mak. If new extension .dlls containing new user functions are to be used, they must be listed in the SQR Extension section in pssqr.ini in the system directory.

For any ufunc, you must register it by making the following call in InitSQRExtension():

lpfnUFuncRegister(struct ufnns* ufunc);

The function pointer, lpfnUFuncRegister, is passed in from the calling module. Refer to extufunc.c for the definition of struct ufnns and the sample user functions.