Hi,
Thanks for the response, unfortunately the %merged parameter is not available when just looking at difference between two revisions.
I am not ready to merge as there are many files in many changesets that cannot be easily excluded and most of the changes are not appropriate for the branch I am working on.
This seems to be a common scenario that just isn't handled very well in TortoiseSVN - there was a fix made in the trunk that was a part of larger changeset and I would like to apply it to a branch that was created on a tag long before the fix.
The easy way would be to use 3 way merge tool with changes on left and middle and working copy on the right. I can do this manually but it requires a lot of manual work when there are a number of files changed.