What is the type of property that you want to bind? I did not quite understand why you might need to have concatenated values of multiple properties for one property directly. Is that a list-like data structure? It would be helpful if you could provide more detail.
Thanks
Elif
Well there are some ways to workaround the issue but i guess they would be even worse than having a property on the workflow that would deal with this. I still will tell the ways that come to my mind:
1. Have your DeleteFilesActivity a gray box composite activity that you can drop a Policy activity in and set your Path in that Policy activity
2. Have x number of properties x being the number of different properties that you might want to bind to as in PathVar1, PathVar2, or Folder1, Folder2...etc in your custom activity. The user would set each of those folder names and in your custom activity set the Path to be the concatenation of whatever values you may have other than null for each of those properties based on how many of them are bound/set.
I will post more ways once i come up with more, however i dont think we provide such "concatenated" binding for a property.
Thanks
Elif