Hello!! how are you all??

I want to make a dll that will work on all windows systems (even those
without the .Net framework).
the dll will only need to do three simple tasks:
1. search for a file. (already solved it in a different post..)
2. read/write to a file...
3. execute commands from the command prompt...

I thought i should create the dll in c++, but it is harder that I thought...
I know some c#, but the syntax doesn't seem the similer at all...

can anyone pls help me with this project??

I will be very grateful!!

thanks!!!