Thank you for your response. Yes sure I can write a MATLAB code, which explicitly shall define which elements and nodes should be assigned what numbers. However, I am unaware of what should be the format and pattern of the code, such that it could smoothly be imported into the external model module. Could you kindly provide an example here?

Plus, the type of MATLAB file where code is written would be .m, and I don’t know how to relate this type of file with the required types, as like you have mentioned in your reply, namely .cdb or ds.dat. 

And one more thing, does there exist a possibility to insert an APDL command in the mechanical interface, under any of the tabs like Geometry or Mesh located in the Model tree, such that it can enable me to achieve what I want? Thanks.