Pointers in C#

Question

hi, Any one can help me in the following i have two functions in "dll.dll" as int addition(int a,int b); char* functionname (char* string); i'm calling this function in C#.NET program using [DllImport("dll.dll")] static extern int addition(int a,int b); how can i declare the character pointer in C# . but i didn't try IntPtr,can any one help me using unsafe code. Thanks prakash