<formtoemail_value value_name/>
Value_name is a custom value. It should take the value of the "name" parameter of the <input> tag and be assigned to the "value".
Example:
<input type="text" name="telephone" value="<formtoemail_value telephone/>">
You can use this tag only in html mode and at the very beginning of the html text you should type <advancedparser/>followed by the tag <loadmodule formtoemail/>.