here is the p6 fix

1. Create a working directory (c:\tempextproc for example), and place the following code in a file called  getempno.pc  
   
   /* getempno.pc */
   
   #include <sqlca.h>
   #include <oci.h>
   int __declspec(dllexport) get_empno(OCIExtProcContext *epctx)
   {
   int empno=0;
   EXEC SQL REGISTER CONNECT USING :epctx;
   EXEC SQL SELECT empno INTO :empno FROM emp where ename='KING';
   return(empno);
   }
    
2. Open a Visual Studio command prompt (Start > Programs > Microsoft Visual Studio 2008 > Visual Studio Tools > Visual Studio 2008 Command Prompt ,   and move the command prompt into that irectory.
    
3. Set ORACLE_HOME and MSVCDIR environment variables by issuing the following at a command prompt (adjust paths for your environment):
   
   set oracle_home=D:\oracle\product\11.2.0\dbhome_1
   
   set MSVCDIR="D:\Program Files\Microsoft Visual Studio 9.0\VC"
4. Precompile the .pc file using the following command (all on one line), which will result in the creation of getempno.c :
   
   proc iname=getempno.pc oname=getempno.c parse=full include=%ORACLE_HOME%\oci\include include=%ORACLE_HOME%\precomp\public include=%MSVCDir%\include
    
5. Compile getempno.c with the following command (all on one line), which will result in the creation of getempno.dll 
   
   cl -I%ORACLE_HOME%\oci\include -I%MSVCDir%\include -I%ORACLE_HOME%\precomp\public -Zi getempno.c /LD /link %ORACLE_HOME%\oci\lib\msvc\oci.lib %ORACLE_HOME%\precomp\lib\orasql11.lib msvcrt.lib /nod:libcmt /DLL
    
6. In this case, we'll copy the dll to %ORACLE_HOME%\bin for simplicity
   
   copy getempno.dll %ORACLE_HOME%\BIN\getempno.dll
    
7. At this point, getempno.dll will have a dependency on MSVCR90.DLL which likely does not exist in the PATH, so it will need to be copied to %ORACLE_HOME%\bin, or the following error will result at runtime:
   
   ERROR at line 1:
   ORA-06520: PL/SQL: Error loading external library
   ORA-06522: Unable to load DLLERROR at line 1:
   ORA-06520: PL/SQL: Error loading external library
   ORA-06522: Unable to load DLL
   First, however, it will need to have the manifest incorporated into it or the following error will result at runtime:
   
   
   Microsoft Visual Studio C++ Runtime Library
   ==================================
   Runtime Error!
   
   Program: d:\oracle\product\11.2.0\dbhome_1\bin\extproc.exe
   
   R6034
   An application has made an attempt to load the C runtime library incorrectly.
   Please contact the application's support team for more information.
   To create the manifest, move the VS2010  command prompt into the MSVCRT redistributable folder and issue the following:
   
   cd %MSVCDIR%redist\x86\Microsoft.VC90.CRT
   
   mt.exe -manifest Microsoft.VC90.CRT.manifest -outputresource:msvcr90.dll;2
   for further information, refer to MSDN Documentation
    
8. After incorporating the manifest, copy MSVCR90.dll to %OracleHome%\bin
   
   copy msvcr90.dll %ORACLE_HOME%\bin\msvcr90.dll
9. Now, connect in SQL*Plus for example 
   
   sqlplus scott/tiger
   and create the library, create the procedure wrapper, and test it by running the code below
   
   drop library empnolib;
   /
   create library empnolib as 'D:\oracle\product\11.2.0\dbhome_1\bin\getempno.dll';
   /
   create or replace function get_empno
   return binary_integer as
   external library empnolib
   name "get_empno"
   language C
   with context
   parameters(context);
   /
   
   select getempno from dual;
10.  
11. also look at the microsoft fix

https://msdn.microsoft.com/en-us/library/ms235560(VS.80).aspx