Known evolutionary mechanisms usually operate on populations (of cells or organisms) by adapting in several cycles of genetic change (aka duplications, deletions, point mutations etc.) and natural selection. They are usually able to modify an existing mechanism coded in the DNA, operating on a similar molecule to a new mechanism, all this over a relatively long period of time. This is essentially Darwinian evolution.

What you define as a "mechanism to study a compound and code a DNA sequence for it" sounds very Lamarckian at best. But actually, nature evolved such mechanisms for special purposes, such as innate immunity in mammals, where the organism essentially "studies" antigens in the environment and grows white blood cells with proper DNA sequences to fight the carrier of that antigen.

 Thank you Dr Mate

You are right that cells and organisms are developed by trial and error method that is various mutations...and it took very long period to develop a complex organism.

But still I hope that there may be mechanisms to adopt a new code for new compound as you explained in immune system.

I would like to explore more in this question.

Thank you once again.