Asm Add New Feature and Modify in Exe file that is coded in C++/C#/VbScript

I have exe files which is old mmorpg games. this game open in 2003 and close project in 2007. i need asm skills to add new feature in this exe files and modified the feature it has. its very complicated but as long as you are professional, you can do it. i need help to modified each thing in this exe files. i will put some guide about what to changes and what to add. normally, to modify the files is not taking longer time since you can attach it in Debugging software such as Ollydbg etc. to modify it it only take's 1 - 10 minute depend on your skills. but to add new feature maybe it need some time up to 3days . because it is older files and does not have any protection in the files. for better modifications, its recommend to reverse engineering first for the source files in c++/C# + Vbscript in it. We will do this in T**M****R for better working to be done.