[Feature request] Allow to launch the FileOpen / FileSave dialog in a standard directory

Is there an existing issue for this?

• I have searched the existing issues

Description of the Issue

This issue stems from the discussion on the forum: https://community.notepad-plus-plus.org/topic/27270/set-current-directory-to-default-if-no-real-file-is-open

For untitled tabs, I'd like to be able to launch the "Open File" or "Save File" dialog in a standard directory -- regardless of the directory of the last active real file.

This should allow for me to better handle the following situation:

1. The setting "Default Open/Save file Directory" is set to "Follow current document"
2. I have a tab with new contents (not yet saved as a file)
3. In another tab, I have a file from a network folder, which is the active tab now.
4. I close the tab with the network file. Only the untitled tab remains
5. Now I want to save this untitled tab to a "standard" folder. The standard folder is the one used after Notepad++ is started without any files. It's "Desktop" for me.

As of now, when I press Ctrl+S in the step 5, the dialog opens in the network directory. I'd like it to open in the "Standard" directory. But this should only be for untitled tabs. For real files, the dialog should still open in the directory of the file.

Describe the solution you'd like.

Maybe another command to launch the Open/Save dialog in a standard directory (which could be configurable via settings, but not necessarily).

Debug Information

Notepad++ v8.8.8   (64-bit)
Build time: Nov 16 2025 - 20:55:01
Scintilla/Lexilla included: 5.5.7/5.4.5
Boost Regex included: 1_85
Path: C:\Program Files\Notepad++\notepad++.exe
Command Line: CustomFileDialog.cpp
Admin mode: OFF
Local Conf mode: OFF
Cloud Config: OFF
Periodic Backup: ON
Placeholders: OFF
Scintilla Rendering Mode: SC_TECHNOLOGY_DIRECTWRITE (1)
Multi-instance Mode: monoInst
asNotepad: OFF
File Status Auto-Detection: cdEnabledNew (for current file/tab only)
Dark Mode: OFF
Display Info:
    primary monitor: 1920x1080, scaling 150%
    visible monitors count: 1
    installed Display Class adapters: 
        0000: Description - Intel(R) HD Graphics 620
        0000: DriverVersion - 31.0.101.2111
        0001: Description - Intel(R) UHD Graphics 620
        0001: DriverVersion - 31.0.101.1999
        0002: Description - Intel(R) HD Graphics 630
        0002: DriverVersion - 31.0.101.2130
OS Name: Windows 10 Pro (64-bit)
OS Version: 22H2
OS Build: 19045.6456
Current ANSI codepage: 1252
Plugins: 
    DSpellCheck (1.5)
    HexEditor (0.9.12)
    mimeTools (3.1)
    NppConverter (4.7)
    NppExport (0.4)
    PythonScript (2)

Anything else?

Disclaimer: I also submitted this as an issue in the Python Script plugin for the case that this feature is better implemented in a plugin and not in the "main" Notepad++.

Start by reading CustomFileDialog.cpp, the only source file named in the issue, and trace how Open and Save dialogs choose their initial directory for untitled versus real documents. Compare that behavior with the forum scenario and the existing “Follow current document” setting. Done means untitled tabs use the standard directory while real files continue using their own directory.