You want to allocate the memory dynamically. Like this:
char** randomfunction() {
char **k=malloc(sizeof(char*)*20);
int i;
for (i=0;i<20;i++)
k[i]=malloc(sizeof(char)*10);
//populate the array
return k;
}
int main() {
char** arr;
int i;
arr=randomfunction();
//do you job
//now de-allocate the array
for (i=0;i<20;i++)
free(arr[i]);
free(arr);
return 0;
}