Changing from <string> to <cstring>

[l0ckz0r]

I came across a problem that I used to <string> to solve, apparantly i was jumping the gun and im supposed to use <cstring>

How would i re write:
void searchDate()
{
char dateSearch[99];
size_t i;
string line;


cout <<"Enter a date you wish to search by: ";
cin.getline(dateSearch, 99);

ifstream bookcopy ("bookcopy.txt", ios::in);

while(getline(bookcopy,line))
{
i = line.find(dateSearch);
if(i!=string::npos)
{
while(line.find("#")!=string::npos)
line[line.find("#")] = '\n';


cout << line << endl;
}
}

so that it doesnt use things to do with <string>?