I would like to do this:

replace the word "prod" with the word "special" but it may occur through the file naturally without a command, I only want it to happen when it has a specific command in front of it. The command will always look like this

<IMG,###,###,##,>prod/directory/IMG/file

Now the numbers (parameters can happen numerous times or not ) so it can look like this <IMG,320,123,2,2,1,1,1,1,2>prod/... or like this <IMG,100,100,2,2>prod/...

What I have at the moment is sed s/"\>prod"/"\>special"/g but I want it to include the command as the regex and it has to go back in front of the word the same way.

Any suggestions to a safer regex?

I was thinking something like this or along these lines: (but it doesn't work and i am not really familiar with the ".*")

sed s/\(IMG,.*\)prod/\1special/

Thanks in anticipation!

Try:
sed 's=\(<IMG,[0-9,]*>\)prod/=\1special/='

that works great, except:

but I was also wondering is there a way around if the IMG call was in lowercase (sorry, I neglected this before). I guess something like (IMG|img)...?

Secondly can you please explain exactly what is happening here (it makes it simpler for me to not need to ask the next time when something similiar comes up). I've been referencing a couple of books and I don't think I've seen before the "=" used in the sed command. The man page doesn't tell me much either.

Thanks again, much appreciated!

Try:
sed 's=\(<[Ii][Mm][Gg],[0-9,]*>\)prod/=\1special/='

As for the equals sign, my sed man page, as it describes the s command, says "Any character can be used instead of /." Slash wasn't a good choice here since the data also contains a slash. Had I used a slash for the delimiter, I would have had to backslash any slashes that weren't delimiters. Switching delimiters eliminates the need for the backslashes.

but thats even better than brilliant

Thanks!!