If you want to be able to start a bat, cmd, exe, com or other executable from the same directory as where you have a batch file. Like this, in the directory c:\private\scripts    you have a batch file called start.bat
In that file you want to start the file calc.exe

Check this out..

%0 has the full name of the batch file, including the path. To change to the directory where the batch file is, you'd want to do:

cd %0\..\

You can run a program in the same directory as the batch file by doing:

%0\..\myreallylongexecutablefilename.exe

So starting calc.exe in the directory c:\private\scripts would mean you put this inside a bat file.
%0\..\calc.exe