c++ - Get relative path to current dll from working directory -

i'm using software loads .dll library sofware located somewhere on my hard drive, let's say:

c:\program files\unicode chars\(...)\123.exe 

and dll located in:

c:\program files\unicode chars\(...)\addons\dlls\123.dll 

now need able perform operations fopen(), fclose() etc inside of dll, passing path dll fopen parameter.

how relative path 123.dll allow me access file short, ansi path, possibly

addons\dlls\123.dll