To Create a floating palette in Acrobat/Photoshop plugin two simple steps are needed –  use CreateDialog() and ShowWindow() along with SDK specific floating palette flag (if any needed).   First Step is to create palette by using CreateDialog(). // Get the parent window HWND here. either use your SDK API’s or WIN32 API’s HWND hParent = WinAppGetModalParent(AVAppGetActiveDoc()); //Acrobat specific   HWND hParent = GetActiveWindow(); // WIN32 API, use it in photoshop        // Create the floating palette window and register callbackMyPaletteProc HWND dialog = CreateDialog(gHINSTANCE, // it is instance handle of the plug-in                          MAKEINTRESOURCE(IDD_DIALOG1), // use resource dialog, IDD_DIALOG1 is the id of your     dialog in resource.                          hParent,  // parent application HWND                          (DLGPROC) MyPaletteProc); // callback function   In Photoshop use: GetDLLInstance(gPlugInRef) in place of gHINSTANCE

Second step is to Register palette with Application and Show palette at WM_INITDIALOG opcode. // here comes the dependency with SDK, you need to findout the API to register dialog and flag for floating palette.   // for acrobat SDK use following: sAVWin = AVWindowNewFromPlatformThing(AVWLfloating, 0, NULL, gExtensionID, hWndDlg);   // for photoshop plug-in, no registration required, just call ShowDialog.   // call this function to display palette on top. If you missed this, palette will remain invisible ShowWindow(hWndDlg, SW_SHOW); Complete code for Acrobat Plug-in is:

HWND dialog = NULL;
void CreateDialog()
{
    INT_PTR nRetVal ;
    HWND CapturehWnd, hParent;
    CapturehWnd = GetCapture();
    
    if ( CapturehWnd != NULL )
    {
        ReleaseCapture();
    }
    hParent = WinAppGetModalParent(AVAppGetActiveDoc());
    dialog = CreateDialog(gHINSTANCE, MAKEINTRESOURCE(IDD_DIALOG1), hParent, (DLGPROC) MyDialogProc);
    
    if ( CapturehWnd != NULL )
    {
        SetCapture( CapturehWnd );
    }
}

LRESULT CALLBACK MyDialogProc(HWND hWndDlg, UINT Msg, WPARAM wParam, LPARAM lParam)
{
    switch(Msg)
    {
        case WM_INITDIALOG:
        {
            sAVWin = AVWindowNewFromPlatformThing(AVWLfloating, 0, NULL, gExtensionID, hWndDlg);
            ShowWindow(hWndDlg, SW_SHOW);
            return TRUE;
        }
        break;
        case WM_COMMAND:
        {
            switch(wParam)
            {
                case IDOK:
                {
                    // TODO:: Write code here for OK button click handling
                    EndDialog(hWndDlg, 0);
                    return TRUE;
                }
                break;
                case IDCANCEL:
                {
                    // TODO:: Write code here for CANCEL button click handling
                    EndDialog(hWndDlg, 0);
                    return FALSE;
                }
                break;
            }
        }
        break;
        case WM_DESTROY:
        {
            AVWindowDestroy(sAVWin);
        }
        break;
    }
    return FALSE;
}

Now call CreateDialog() function where you want to instantiate your palette, at Menu item click probably.