@gioma
As I said just above, I would rule out using the Clipboard, and instead adopt a safer route like:
PC1_aplicativoA sends the files to PC2 in a specific folder to receive the files (PC2_folderDownloadedFromPC1);
PC2_aplicativoB monitors this folder from time to time, to check if a new file has been posted there (you could use a list to control the files already worked on, or even the date/time of the last jobs done, that is, if there are a new file, its creation date and time will be the latest in the folder);
if there are new files in the folder (PC2_folderDownloadedFromPC1), then PC2_aplicativoB will be able to carry out the desired actions, and, clean the list or control date/time;
as already mentioned, you can test whether the file has already completed its transfer from A to B, just by trying to open the file exclusively.
This way, you will always have greater control over what has been processed or not, and you will no longer depend on the data in the Clipboard's memory (which can be easily changed by other applications on the PC2);