You're talking about the Commodore 64, aka CMB 64.
Virtual tape is a storage system that, er, virtualises the system of tapes. So what I think you're trying to say is that you've got a movie file downloaded and you're trying to play it.
The C64 is a keyboard with a processor that runs on BASIC.
Assuming you've already gotten the virtual tape downloaded, you just press the play button or whatever.
Primitive computers like the C64 should have mouses installed - like the Commodore 1351 - but this is not necessary.
I'm young, so I don't really understand computer life before the graphic interface. But can't you just insert the BASIC code that runs the virtual tape?
Apparently you can just put PRINT or LIST to play the tape.
However, I don't think BASIC does the whole download/replay thing - it only runs programs in its language.
(Summed up from Wikipedia)
Maybe ask an expert? Sorry...
Thank you and have a nice week! :)