Hi Ashwin,
When you're trying to compile a MEX file, you typically need to provide the source code file(s) that should be compiled, and possibly additional flags or options as required.
The command you've written appears to be trying to link a pre-compiled library "libIp_xfft_v9_0_bitacc_cmodel.lib" rather than compiling source code. If you have the source code files (usually with extensions like .c, .cpp, .cxx, .f, etc.), you should specify those in the "mex" command.
Given that you have a ".dll" and ".h" files, you might be looking to create a MEX file that interfaces with the DLL. If that's the case, you'll need to provide the source code that includes the header file and calls the functions in the DLL.
If you're not sure what source code to compile or how to write the wrapper, you'll need to consult the documentation for the library you're using or seek out examples of how to interface with it from MATLAB. Here is the link for the same: https://www.mathworks.com/help/matlab/ref/mex.html.
Hope this helps!
