Closing an Excel Application using Outlook VBA after using an Excel function - excel

Question

I am working on a sort of "BOT" for Outlook (using Outlook VBA), in which I receive info by mail, split the mail body, paste it on Excel and execute Excel macros.
After adding the part where I call the Excel macro, I get
'1004 - application-defined or object-defined error'
if I'm running this for the second + time.
xlApp.Application.Run "AINT.Cali_B_Click"
Even though I'm setting my Excel variables to nothing and using .close and .quit, Excel is still running.
How can I end the application reference that is keeping Excel open?
Here's my full code:
Private Sub inboxItems_ItemAdd(ByVal Item As Object)
On Error GoTo ErrorHandler
Dim Msg As Outlook.MailItem
Dim MessageInfo
Dim Result
Dim splitter() As String
Dim splitter2() As String
Dim loopH As String
Dim str As Variant
Dim LoopCali As Integer
Dim i, j As Integer
Dim xlApp As Object
Dim sourceWB As Object
Dim Header, QuoteSTG, AINT, Treinamento As Object
Dim strFile, file_name As String
Dim shellcom As String
i = 1
If TypeName(Item) = "MailItem" Then
If InStr(Item.Subject, "BOT") > 0 Then
splitter = Split(Item.Body, vbCrLf)
Set xlApp = CreateObject("Excel.Application")
strFile = "C:\Users\e1257539\Desktop\SMOBOT\SMO_TOOL_BOT.xlsm"
With xlApp
.Visible = False
.EnableEvents = False
.DisplayAlerts = False
End With
Set sourceWB = Workbooks.Open(strFile)
sourceWB.Activate
Set Header = sourceWB.Sheets(4)
Set QuoteSTG = sourceWB.Sheets(13)
Set AINT = sourceWB.Sheets(7)
Set Treinamento = sourceWB.Sheets(10)
file_name = QuoteSTG.Range("A" + CStr(QuoteSTG.Range("B1").Value2)).Value2
QuoteSTG.Range("A" + CStr(QuoteSTG.Range("B1").Value2)).Value2 = ""
If splitter(2) = "Calibração" Then
loopH = splitter(26)
LoopCali = CInt(loopH)
sourceWB.Save
Header.Range("D6").Value2 = splitter(22)
Header.Range("D8").Value2 = splitter(12)
Header.Range("F4").Value2 = "AINT"
Header.Range("F3").Value2 = "EXW"
Header.Range("C2").Value2 = file_name
Header.Range("C4").Value2 = "Calibração"
Header.Range("L2").Value2 = "30"
Header.Range("K12").Value2 = Item.Subject '< criar string?
j = 40
For i = 1 To LoopCali
splitter2 = Split(splitter(j), "-")
AINT.Range("N7").Value2 = splitter2(0)
AINT.Range("N13").Value2 = splitter2(1)
j = j + 2
If splitter(j) <> "" Then
AINT.Range("N14").Value2 = splitter(j)
End If
j = j + 2
If splitter(j) <> "" Then
AINT.Range("N16").Value2 = splitter(j)
End If
j = j + 2
If splitter(j) <> "" Then
If splitter2(0) <> "RMT" Then
AINT.Range("N15").Value2 = splitter(j)
End If
End If
j = j + 2
If splitter(j) <> "" Then
AINT.Range("N17").Value2 = splitter(j)
End If
j = j + 2
xlApp.Application.Run "AINT.Cali_B_Click" '< calling the excel sub
Next i
End If
End If
End If
'Closing excel
MkDir "C:\Users\e1257539\Desktop\SMOBOT\" + file_name
sourceWB.SaveAs FileName:="C:\Users\e1257539\Desktop\SMOBOT\" + file_name + "\" + file_name
sourceWB.Close (False)
xlApp.Quit
Set xlApp = Nothing
Set sourceWB = Nothing
Set AINT = Nothing
Set QuoteSTG = Nothing
Set Header = Nothing
ErrorHandler:
MsgBox Err.Number & " - " & Err.Description
If Not sourceWB Is Nothing Then
sourceWB.Close (False)
End If
If Not xlApp Is Nothing Then
xlApp.Quit
End If
Set xlApp = Nothing
Set sourceWB = Nothing
Set AINT = Nothing
Set QuoteSTG = Nothing
Set Header = Nothing
End Sub

Answer 1

Turns out using xlApp.Application.Run "AINT.Cali_B_Click" or xlApp.Application.Run sourceWB.Name & "AINT.Cali_B_Click" left open references on the VBA code.
The way to call the code without lefting any open is using CallByName,
As in Call CallByName(AINT, "Cali_B_Click", VbMethod)
This way the VBA code can call the function and run as many times as needed without the current error.