看来只能通过修改别人的代码搞了。
我刚搜到一段代码(不知道这里支不支持贴代码,顺便贴个原文链接吧:
http://www.latest-techtips.com/2012/09/how-to-add-paypal-donation-button-on.html):<pre>
<center>
<form action="
https://www.paypal.com/cgi-bin/webscr" method="post">
<!-- Identify your business so that you can collect the payments. -->
<input type="hidden" name="business"
value="Your Pay Pal ID" />
<!-- Specify a Donate button. -->
<input type="hidden" name="cmd" value="_donations" />
<!-- Specify details about the contribution -->
<input type="hidden" name="item_name" value="Donation for business name" />
<!-- Specify details about the contribution (Donation Details)-->
<input type="hidden" name="item_number" value="Reason why you need Donation?" />
<!-- Specify details about the contribution -->
<input type="hidden" name="currency_code" value="USD" />
<!-- Display the payment button. -->
<input type="image" name="submit" border="0"
src="
https://www.paypal.com/en_US/i/btn/btn_donate_LG.gif"
alt="PayPal - The safer, easier way to pay online" />
<img alt="" border="0" width="1" height="1"
src="
https://www.paypal.com/en_US/i/scr/pixel.gif" />
</form>
</center>
</pre>