Dynamic link libraries can be used from both WXLS and 32, but WXLS can only use 16-bit DLL's and 32 can only use 23-bit DLL's.
Dynamic Link Libraries (DLL's) can be used to provide additional cursor resources created with SDK or other toolkits, or to provide dynamically callable subroutines. The file xlsx.c contains startup and cleanup code for a DLL that seems to work with Borland C++. This code can be linked with cursor resources or with code into a DLL.
Once you have a DLL, the function load-dll can be used to load a DLL. The return value of this function is an integer representing the DLL handle. The function free-dll can be used to release the library.