what is user that executes windows batch file

Question

I have .bat file which works with network path using directory stack and therefore needs network privileges. My PC is member of domain. And here is strange thing: when I run batch file using double click on it - it works. If I will choose "Run as diffrent user" and enter my credentials such as DOMAIN\USER and password - this batch file works not properly. Therefore question - under which user batch file is executed when clicked? UAC is turned off I believe.

EDIT

here's batch script:

for /r %%F in (Output_AutomatedBuild\TestsResults\Coverage\*.cover.xml) do (%
xslt2xml.exe ncover2newncover.xsl %%F %%F
)

here's C# source code of xslt2xml.exe program:

class Program
{
    static void Main(string[] args)
    {
        try
        {
            XslTransform myXslTransform;
            myXslTransform = new XslTransform();
            myXslTransform.Load(args[0]);
            myXslTransform.Transform(args[1], args[2]);
        }
        catch(Exception ex)
        {
            Console.WriteLine("Exception:");
            Console.WriteLine(ex);
        }
    }
}

As you can see exception won't be thrown so exit code always be equal to zero.