I figured it out after trying some more and thought that might be of interest to others.
Code
function main()
{
int i;
for (i = 0; i < 10; i++) {
printf("i ist %i", i);
if (i == 0) {
string Name = file_next("CollectedHistory\\*.csv");
printf("Der Filename lautet: %s \n", Name);
}
else {
string Name = file_next(0);
printf("Der Filename lautet: %s \n", Name);
}
}
}