I'm using labelxs, or label 1.99, or whatever it is... it says:

"LabelOnDrop
Sets an action to perform when a file or a folder is dropped on the label.
The full path to the file/folder is passed to the action as an argument."

So I tried doing it this way, which works for other bangs/programs:

FTPdropOnDrop !execute [!FTPConnect ] [!FTPSend "%{args}" "%{RemoteFile}"] [!FTPDisConnect]

Unfortunately this isn't doing the trick...