[NEED HELP] Can´t send strings + list of strings

[Luzifer]

I´m working on a remote file browser atm and I found a function on the internetz which gives me all files and folders of a drive in a string list. Now I need to send a command to the client which tells the client this list and what to do with it. Looks like this now:

Code:

SendData("Add|" & GetFileList(SplitData(1)))

But I get an error that the &-operator is not defined for string and System.Collections.Generic.List(Of String). What can I do?
Any help is appreciated =)