Chey:
- Do you have experience in basic HTML?
- Did you write the PHP script?
I have the feeling that the answer to both questions is NO.
It is not a very wise idea to mess with code you do not understand, so -pat on the shoulder- good on you for not wanting to do so.
I assume that you have a config.php or a language.php file somewhere included (look in the script for "Required" or "Include" commands. This is the file you might want to adjust.
If you hgave found that file, you are going to look for (And again, I am guessing here):
1: $msg_reply = "reply";
or:
2: $msg_reply = "<a href=\"".$reply_url."\">reply</a>";
And replace that for:
In case 1:
$msg_reply = "<img src=\"reply.gif\">";
in case 2:
2: $msg_reply = "<a href=\"".$reply_url."\"><img src=\"reply.gif\"></a>";
where reply.gif is the name of the picture with the word reply, and you should include the relative path to that file in the link.
Please note: This will most likely result in the whjole site being modified; all \occurances might be replaced.
A completely other way to do this (I am assuming you want some fancy colors and lines around the link) is to use CSS. If you have a look at my site, my navigation does not use images. It is all done using a piece of formatting code, called CSS (Cascading Style Sheets).
I think this will give you something to breed on.