Took me a bit of investigation, looks like Zoiper5 does not accept the ControlClick, something I stumbled over and resigned before, you made me reconsider it and it looks like the following works.
Please be aware that there still might be quite a lot of inconsistence because of the dynamic gui of Zoiper5. I would appreciate it if we could stay in touch to improve the whole stuff.
#NoEnv ; Recommended for performance and compatibility with future AutoHotkey releases.
SendMode Input ; Recommended for new scripts due to its superior speed and reliability.
DetectHiddenWindows, on
global ZoiperOK1x := 200
global ZoiperOK1y := 145
global ZoiperESC1x := 230
global ZoiperESC1y := 140
^Numpad0::
;Zoiper5 end call 1
id := WinExist("Zoiper5")
WinActivate, ahk_id %id%
MouseClick, left, %ZoiperESC1x%, %ZoiperESC1y%
return
^NumpadEnter::
;Zoiper pickup call 1
id := WinExist("Zoiper5")
WinActivate, ahk_id %id%
MouseClick, left, %ZoiperOK1x%, %ZoiperOK1y%
return
Cheers
Niko