Here's my attempt at modifying the previous example to work with the new parameters and parameter order... please feel free to correct anything I've misunderstood.
#region Hoster demo addbutton
opt ("WinTitleMatchMode", 2)
#include <ANYGUI.au3>
#include <GUIConstants.au3>; must be included in main script for GUI Functions to work
Dim $myVar1, $myVarB1, $myVarB2, $myVarB3, $myVarB4, $myVarB5, $myVarB6, $myVarC1
Run('C:\Program Files\Micro Technology Unlimited\Hoster Demo\Hoster-demo.exe')
Sleep(8000)
WinActivate("Dialog")
ControlClick("Dialog", "Demo", 1); clears demo dialog box
WinSetState(" - Hoster", "", @SW_MAXIMIZE)
Sleep(2000)
ControlMove("Hoster", "", 1017, 20, 239, 700, 463)
$myVar1 = _GuiTarget("Hoster", "", "", 59648);<===Target is control on main application.
$myVarB1 = _TargetAddButton("Test", 750, 20, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarB2 = _TargetAddButton("Test", 860,20, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarB3 = _TargetAddButton("Test", 750,80, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarB4 = _TargetAddButton("Test", 860,80, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarB5 = _TargetAddButton("Test", 750,140, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarB6 = _TargetAddButton("Test", 860,140, 100, 50, "", "", $myVar1)
GUISetState(@SW_SHOW)
$myVarC1 = _TargetChildCreate("Testing", 730, 200, 300, 600, $myVar1)
GUISetBkColor(0xff00)
GUISetState(@SW_SHOW)
While WinExists($myVar1)
Sleep(100)
If Not WinExists($myVar1) Then
Exit
EndIf
WEnd
_EndTarget()
#endregion