Aldrin Almia:
I'm doing try and error since I'm new to this one and I'm not familiar to the code.
Try and error without knowing at least basics before is one of the worst approaches I know. Learn C and C++at first (buy a book, download some tutorial, install GCC GNU compiler and write some code) and when you will know how to write own code and read a code of others, start with MDL API.
Aldrin Almia:
Sir, may I know on what part of the code I'm mistaken?
Are you serious with this question? Did you OPEN and READ MDL documentation and check what is the definition of mdlElement_setSymbology? If I remember right, there is even short example for this function in the documentation. And I showed it clearly to you already in my previous answer: The function requires 4 arguments. Do you use 4 arguments in your code?
Until you will start to behave in a professional manner, which means to study the standard documentation (and also study h and fdf files as adviced by Jon Summers) before you will ask, there is no way how to help you efficiently.
Aldrin Almia:
The truth is, I'm very serious learning MDL
No, you don't. To put pieces of code, which you don't understand, together and to hope it will work, is not serious learning. After you will start read documentation, C/C++, Visual Studio, MDL API etc., you will learning.
Regards,
Jan