Use right-click and then `f` to change underline style for XChange Viewer

xchange_viewer_underline_change.ahk

#IfWinActive ahk_exe PDFXCview.exe
; Note, this script is built on one major assumption:
    ; 1. that there is a labeled routine called CenterMouseOnActiveWindow, from: https://www.autohotkey.com/boards/viewtopic.php?t=60433
    ; 2. that the Property window shall open at the **center** of the active window. For XChangeViewer, this is exactly the case.
    ~RButton::
        Hotkey, f, f, On
        KeyWait, f, D T3
        Hotkey, f, f, Off
        if(!ErrorLevel) {
            ; Send, {Esc}
        send {up}
        send {enter}
        ; Look for Appearnce piece
            Gosub, CenterMouseOnActiveWindow
            ; To get this "routine", use: 
            MouseMove, -300, -145, 0, R
            sleep 600
            MouseClick, left
            Gosub, CenterMouseOnActiveWindow
            MouseMove, 15, -147, 0, R
            sleep 600
            MouseClick, left
        }
    return
#IfWinActive

; Helper piece:
CenterMouseOnActiveWindow:
; Source: https://www.autohotkey.com/boards/viewtopic.php?t=60433
    Sleep 50
    CoordMode,Mouse,Screen
    WinGetPos, winTopL_x, winTopL_y, width, height, A
    winCenter_x := winTopL_x + width/2
    winCenter_y := winTopL_y + height/2
    DllCall("SetCursorPos", int, winCenter_x, int, winCenter_y)
return

See it in action :)

Note, the AHK script only attempts to open the dropdown list for underline style