After some research about dependencies of nicaiu.dll, I discovered that all the dependencies of the dll file must be solved for it to be loaded correctly. So, I had to point this to its original location (C:\Windows\System32) to solve this problem! So my loadlibrary call would look like:-
loadlibrary('C:\windows\system32\nicaiu.dll','nidaqmx.h','alias','ni');
With the above, my problem is resolved. Alternatively, there must be some way of adding the above path to the loadlibrary's location-to-look-for-libraries. For now, I shall close this question.