Saving into invisible folders ?

[Richmond]

So, I have a stack with a single card containing:

1. A group "PAIR".

2. A button "Button" containing the following script:

on mouseUp
    set the defaultFolder to specialFolderPath("Home")
    create folder ".myMuck"
    set the defaultFolder to specialFolderPath(".myMuck")
    export snapshot from group "PAIR" to file "PAIR.png" as PNG
end mouseUp

  this all using RevMedia 4.0 alpha on Ubuntu Linux 12.04 (don't ask!).

The script creates the folder quite happily, but then does not
save the snapshot into the folder (presumably because Livecode cannot 'see'
a folder with a dot prefix).

I have run the same script, creating a visible folder "myMuck" and the 
snapshot
is saved.

So . . .

1. Does anyone have any bright ideas about saving (and retrieving) into 
invisible
folders?

2. Can one make invisible folders in this way on Windows?

Richmond.