ok, I got the flash stuff figured out
Here is the match expression
\[flash (?<width>([0-9]+)):(?<height>([0-9]+))\](?<inner>(.*?))\[/flash\]
This is the replace function
<object width="${width}" height="${height}"><param name="movie" value="${inner}"></param><embed src="${inner}" type="application/x-shockwave-flash" width="${width}" height="${height}"></embed></object>
or the plain embed tag you asked about
<embed src="${inner}" type="application/x-shockwave-flash" width="${width}" height="${height}"></embed>
This will match the following
[flash 400:300]test.swf[/flash]
with 400 being the width and 300 being the height and, of course, test.swf being the file/URL you want to show.