You can use JavaScript macros:
Move Up:
editor.ExecuteCommandByID(4193);
editor.ExecuteCommandByID(4269);
document.selection.Paste(eeCopyUnicode);
editor.ExecuteCommandByID(4269);
Move Down:
editor.ExecuteCommandByID(4193);
editor.ExecuteCommandByID(4268);
document.selection.Paste(eeCopyUnicode);
editor.ExecuteCommandByID(4269);
and you can assign these macros to any key shortcuts.