Regex is probably the wrong tool, unless you are trying to match that string as a pattern:
"A slash, followed by two uppercase Alpha, and three digits, then a other slash, followed by ..."
If you want to find an exact string, then use string comparison instead - it's a lot easier and a lot simpler to read!
If you want to match a pattern, then you need to give us a bit more info on what is and isn't allowed where - and what you need to break it into as far as match groups are concerned. Get a copy of
Expresso [
^] - it's free, and it examines and generates Regular expressions.
And try starting with:
/(?<id>[A-Z]{2}\d{3})/(?<productcode>\d{2}_[A-Z]{3})</productcode></id>
Which may cover the first two fields.