I have remote website (not mine)
<input type=text id="num" name="num" size="10" maxlength="10"/>
<a id="setnum" href="#">Send</a>
<span id="result"></span>
Is there any way of seting inputbox and sending a form?
Yes, send a GET or POST (depending on the form's method= attribute) to the location specified in the form's action= attribute including your data in key=value pairs where key is the name= attribute of the input element, and value is the wanted value.
If you want some Google keywords:
How to send a POST request in
<insert your favorite programming language here>