Trying to build a 64 bit DLL

I am trying to build a dll to be used in an application that is 64 bit. I build my model in Simulink and build it. Although the dll is built, I see that it is a 32 bit DLL and I am getting errors when I use it with the application. I see the following in the diagnostics window in simulink.

.......

>call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\VCVARSALL.BAT " x86 ********************************************************************** ** Visual Studio 2017 Developer Command Prompt v15.9.7 ** Copyright (c) 2017 Microsoft Corporation ********************************************************************** [vcvarsall.bat] Environment initialized for: 'x86'

Is there a way I could build a 64 bit DLL ? I am on a 64 bit Windows 10 OS.

[Vishnu Dev Amara]

Did you already find a solution to this problem ? I am facing the same issue as well.