Rewriting unsafe code in order not to have to use it

Question

Hey all I have the following unsafe code that I am looking to have converted into something other than that.

SecureString sString = new SecureString();

sString.AppendChar('8');
sString.AppendChar('1');
sString.AppendChar('*');
sString.AppendChar('Y');
//...more sString.AppendChar('') here
sString.AppendChar('Z');
sString.AppendChar('0');
sString.AppendChar('4');

byte[] secureStringBytes = null;
IntPtr unmanagedBytes = Marshal.SecureStringToGlobalAllocAnsi(sString);

try
{
   unsafe
   {
      byte* byteArray = (byte*)unmanagedBytes.ToPointer();
      byte* pEnd = byteArray;

      while (*pEnd++ != 0) { }

      int length = (int)((pEnd - byteArray) - 1);
      secureStringBytes = new byte[length];

      for (int i = 0; i < length; ++i)
      {
         secureStringBytes[i] = *(byteArray + i);
      }
   }
}
finally
{
   Marshal.ZeroFreeGlobalAllocAnsi(unmanagedBytes);
}

return secureStringBytes;

Would anyone be able to help me out to change the code above so that I wont have to use /unsafe when compiling?