If you're wanting to use PHP to output a variable number of HTML elements, then sure, you could use a form and a simple bit of PHP code to do that - namely a [man]for/man loop. Example:
for($i = 1; $i <= $max; $i++) {
echo "<p>This is a repeated section of HTML!</p>\n";
}
The above code doesn't include the declaration of the $max variable, but it should be fairly obvious what goes in that variable. For example, you could replace $max with the variable containing the max number of frames that the user specified in the form.