lpResult [out]
Type: LPTSTR

The address of a buffer that receives the file name of the associated executable file. This file name is
 a null-terminated string that specifies the executable file started when an "open" by association is run
 on the file specified in the lpFile parameter. Put simply, this is the application that is launched when the
 document file is directly double-clicked or when Open is chosen from the file's shortcut menu.
 This parameter must contain a valid non-null value and is assumed to be of length
 MAX_PATH. Responsibility for validating the value is left to the programmer.

std::string result(MAX_PATH+1,0);
if(32<FindExecutableA(fileW, 0, &result[0]))
{
   QString Name(result.c_str());
   //...
}