For compiler to be able to correctly form the imported function call and organize proper transmission parameters, the full description of functions is needed. Functions having the same names but from different modules can be imported at the same time. Imported functions can have names that coincide with the names of built-in functions. Operation of scope resolution defines which of the functions should be called.Call of Imported FunctionsTo import functions during the execution of a mql4-program, the client terminal uses early binding.
This means that if a program has call of an imported function, the corresponding module (ex4 or dll) is loaded during the program load. Forest,As far as i have experienced during the past 2 years working with MetaTrader, there is no real way to call MQL functions from an external DLL.
Metatrader function unresolved adx import call