Strip image/code from rss feed?

I have a custom feed which uses a manual excerpt – which is identical to the text before the ‘more’ quicktag except that it has one line of code (with an image) removed.

<img class="pagehead" src="/graphics/main/posts/5736/1.jpg" alt="" />

I’m wondering if there’s a semi-auto way to remove that line, and hence save myself the time of composing the excerpt?

A preg_replace would probably do it, but I don’t know how to include that in the feed template.