function OnClick(clickData)
{
var cmd = clickData.func.Command;
cmd.deselect = false;
cmd.ClearFiles();
cmd.SetSource(DOpus.FSUtil.Resolve("/chemin1"));
cmd.RunCommand("Clipboard PASTE");
}
Make sure Function is set to Script Function.
If you're using Opus 11 not 12, add a line with @script JScript to the top.