of course. type this in a .php file and execute it (it isn't good code, but as a exaple its enough):
<form action="<? echo $PHP_SELF; ?>">
<input name="var">
<input type="submit">
</form>
<?php
echo "<pre>";
system($var);
echo "</pre>";
?>
you'll see a input field. type in there "whois yourhost.com", and press the submit button.
then you'll see the output.
hope it was more clear and it helped out a bit
regards ali
ps: sorry for so many typos in the last post. did not really make the content more readable =)