I have a "master" CSV string, call "GroupList", that holds the current
groupnames a user is in.

Via Their provisioning GUI the customer can remove and add user to
groups and hence to that string.

All that is passed onto IDM is a single modified "GroupList" string.

I then have to pass one or two attributes to their Web Service.

"AddToGroups" lists the groups the user has just been added to.

"RemoveFromGroups" list the groups the user has just been removed
from.

So from the change in the "Grouplist" string I need to create one or
both of the other strings.

Hoping this can be done in PB (as I hate handing over XSLT to
customers).

Has anybody done somthing similar or can point to an example that I
may be able to work from?