Basically I need to search in clipboard contents for an IP address and replace it with an address that's in a completely different subnet: (10.10.8.24 to 192.168.8.24 as examples). I tried using the find and replace template in Automator but it simply wasn't working with copied text. I'm also kind of a noob with AppleScript syntax.
You can use this shell command to check for clipboard contents and replace them:
[[ $(pbpaste) == "10.10.8.24" ]] && printf "192.168.10.11" | pbcopy
Basically, this checks if the current clipboard (which pbpaste outputs) is equal to the first string. If it is, it pipes the output of the printf command to pbcopy, which writes to the clipboard. You can add this to an AppleScript and have it repeat with:
repeat do shell script "[[ $(pbpaste) == \"10.10.8.24\" ]] && printf \"192.168.10.11\" | pbcopy; exit 0" delay 1 end repeat
(You have to doctor it up a bit with the \ and ; exit 0 so it runs in AppleScript, but this should check every second and replace the clipboard)