hi, im trying to compile a simple dll but it gives me error.. i trying to create dll so that it can be referenced by vb6

--------------------Configuration: mCodes - Win32 Debug--------------------
Compiling...
StdAfx.cpp
Compiling...
mCodes.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\mCodes\mCodes.cpp(332) : error C2440: '=' : cannot convert from 'char *' to 'unsigned char *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\mCodes\mCodes.cpp(334) : error C2664: 'strlen' : cannot convert parameter 1 from 'unsigned char *' to 'const char *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
Error executing cl.exe.

mCodes.dll - 2 error(s), 0 warning(s)