Send_WM_COPYDATA("Text1|1", "Title")
Send_WM_COPYDATA("Text2|2", "Title")
Send_WM_COPYDATA("Text3|3", "Title")

Send_WM_COPYDATA(ByRef StringToSend, ByRef TargetScriptTitle)
{
    VarSetCapacity(CopyDataStruct, 3*A_PtrSize, 0)
    SizeInBytes := (StrLen(StringToSend) + 1) * (A_IsUnicode ? 2 : 1)
    NumPut(SizeInBytes, CopyDataStruct, A_PtrSize)
    NumPut(&StringToSend, CopyDataStruct, 2*A_PtrSize)
    Prev_DetectHiddenWindows := A_DetectHiddenWindows
    Prev_TitleMatchMode := A_TitleMatchMode
    DetectHiddenWindows On
    SetTitleMatchMode 2
    SendMessage, 0x4a, 0, &CopyDataStruct,, %TargetScriptTitle%
    DetectHiddenWindows %Prev_DetectHiddenWindows%
    SetTitleMatchMode %Prev_TitleMatchMode%
    Return ErrorLevel
}

OnMessage(0x4a, "Receive_WM_COPYDATA")
Receive_WM_COPYDATA(wParam, lParam)
{
    StringAddress := NumGet(lParam + 2*A_PtrSize)
    CopyOfData := StrGet(StringAddress)
	StringSplit, TextArrya, CopyOfData, |
	SB_SetText(TextArrya1, TextArrya2)
    return true
}

SendMessage, 0x40,,,, ahk_id %BarHWND%
SendMessage, 0x42,,,, ahk_id %BarHWND%

OnMessage(0x40, "SetText")
OnMessage(0x42, "SetText2")

SetText()
{
	   SB_SetText("test", 1)
	   return
}
SetText2()
{
	   SB_SetText("test2", 2)
	   return
}

SB_SetText("test", 1)

SendMessage, 0x40,,,, receiver.ahk

OnMessage(0x40, "SetText") 
Gui Add, StatusBar
SB_SetParts(100, 100)
Gui Show, w300 h300
return

SetText()
{
   SB_SetText("test", 1)
   return
}

SB_SetParts(100, 100)

Gui, Add, StatusBar
SB_SetText("This is status bar text")
Gui, Show, w300 h200

ControlSetText, msctls_statusbar321, This is status bar text, A