Couldn't get that to work and tried several variations. Am I right that the aim is to have a string of words (redundant captions) separated by tab spaces in the "Find" box ? Or is there somewhere to change that to camma or... whatever ? I'm ploughing on term by term between other work on the grounds that it works and might take a lot longer to learn a faster way. What happens when a revised folder is re-entered in iMatch database is soul destroying - "64 hours to go" says the info but that's just to make me feel better when it only takes seven and a half. Thanks for suggestions.
I'd suggest doing a text export like Bob suggested, but then use that text file as a Code Replacement file. You would edit the Captions in a text editor (UTF-8 compatible would be best) which should make it easier to trim off the parts you want gone. Then save the file and use it as a Code Replacement file. Then use the IPTC Stationery Pad to bulk apply your corrections to all of your images at once.
If you export like so:
{filename}[tab]{caption}
Then edit the text file and fix up your captions (don't add any other tabs during the editing) and save the file.
Then back in PM, open up the Code Replacement dialog (Edit->Settings->Set Code Replacements...) and Add... your file to the list. Then OK the dialog.
Next, select your images and then open up the IPTC Stationery Pad (Image->IPTC Stationery Pad...) and uncheck all fields. Then find the Caption field and enter your Code Replacement delimiter (default is backslash) and the {filename} variable followed by another Code Replacement delimiter like so:
\{filename}\
This will use the filename of the file currently being processed as the Code to look up the Replacement.
Change the popup menu to the left of the Caption field (under the checkbox) to "Replace".
Apply the IPTC Stationery Pad. It should run through all of your selected images, and correct all of their captions.
Make sure that you don't have any images selected that aren't represented in your text file or their captions will be cleared.
HTH,
-Kirk