Trying to download a file to the appdata directory using libcurl

Question

I am trying to download a zip file from a url and save it on the appdata directory. I am able to get the appdata directory. Only problem is that the getenv("APPDATA") function only puts out char* or std::string but outfilename[FILENAME_MAX] only takes char . Below is my code and I have commented my error exactly so it's easier to see.

I am seeking for a solution to this problem. Thanks for your time!

PS I am open to any suggestions that would reach my end goal of downloading the file to appdata folder. If there is a way that doesn't use curl that's no problem for me:)

#include <stdio.h>
#include <curl/curl.h>
#include <string>
#include <windows.h>
#pragma warning(disable:4996)

using namespace std;

size_t write_data(void* ptr, size_t size, size_t nmemb, FILE* stream)
{
    size_t written;
    written = fwrite(ptr, size, nmemb, stream);
    return written;
}

int main(void)
{
    //Start cURL Download
   
     //following gets the appdata folder
    CoInitialize(0);
    
    char* appdata = getenv("APPDATA");
    strcat(appdata, "\\zip to save.zip");
        printf("Appdata: %s\n", appdata); //this works no problem it prints the appdata location
     
    

    //start cURL download 
    CURL* curl;
    FILE* fp;
    CURLcode res;
    
    char outfilename[FILENAME_MAX] = appdata; //this is the error that fails everything  Error  C2440   'initializing': cannot convert from 'char *' to 'char [260]'
    //Also tried to have appdata as a std::string but it wouldnt take it either
    const char* url = "http://urltozip.com/zip.zip";
    curl = curl_easy_init();
    if (curl)
    {
        fp = fopen(outfilename, "wb");
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
        curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
        res = curl_easy_perform(curl);
        curl_easy_cleanup(curl);
        fclose(fp);
    }

    //End cURL Download
    return 0;
} 

EDIT: This fixed my issues. Thanks to @Hasturkun. I just replaced the upper part of the code with this and completely removed char outfilename[FILENAME_MAX] = appdata; lower in the code.

char outfilename[FILENAME_MAX];
    char* appdata = getenv("APPDATA");
    strcat(appdata, "\\zip to save.zip");
        printf("Appdata: %s\n", appdata); 
        strcpy(outfilename, appdata);

Answer 1

This fixed my issues. Thanks to @Hasturkun. I just replaced the upper part of the code with this and completely removed char outfilename[FILENAME_MAX] = appdata; lower in the code.

char outfilename[FILENAME_MAX];
    char* appdata = getenv("APPDATA");
    strcat(appdata, "\\zip to save.zip");
        printf("Appdata: %s\n", appdata); 
        strcpy(outfilename, appdata);