Ok, understand. Normally I just audit the whole file system to Excel (CSV) using Powershell, drag down a default content type column etc for every file. For the destination filename column I take a copy of the
original file name and then do a search a replace for any special characters which SharePoint won’t allow. After that I then change contents types for the kind of special exceptions that you talk about. Then I run the import.
If your source looks like this;
<ConnectionString>Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Folders.xlsx;Extended Properties="Excel 12.0 Xml;HDR=YES;IMEX=0";</ConnectionString>
And your source (xlsx) must contain the following columns (import key must be a unique number – i..e 1,2,3,4 and ImportStatus must be “Import” for everyrow );
Then the data source will be updated to reflect if the item was successfully imported and any Exception encountered. You can then correct any problems, change import status for those rows and re-run the import.
This is useful for large imports when files fail because they have illegal extensions, are too big, are in use by a user etc.
Will try and post an example in due course