Rewriting the string class

[mmyers]

As an assignment for school, I'm attempting to rewrite the string class. I've gotten a little bit of a block on inserting a string (array of characters) within another string (array of characters) at a specific point (index). I have created a class type of MyString and the content parameter is _string. Here's what I have so far:

void MyString::Insert(const char *CString, int index)
{
    MyString temp;        // define a temp area as a MyString object
    temp._string = new char[ strlen(_string) + strlen(CString) ];
    for ( int i = 0; i < (index+1); i++ )        // copy the first part of the 
        temp._string[i] = _string[i];            // original string
    for ( int j = 0; j < strlen(CString); j++)   // copy the string to insert
        temp._string[j+index] = CString[j];      // into the temp string
    for ( int k = index+1; k < strlen(_string); k++)    // resume copying the 
        temp._string[k+strlen(CString)] = _string[k];   // original string
    strcpy(_string, temp._string);   // copy the temp string as the original
    delete [] temp._string;  // release the memory for temp string
}

I appreciate any comments or suggestions.

Matt Myers
UAT Student