Amélioration des ressources pour Macro VBA recup de données sur un serveur

Sub Recup_PI()

Dim sTagname As String
Dim sTime As String
Dim sServer As String
Dim macroResult As Variant

sServer = "12.123.123.12"

i = 8
j = 8
a = 1
b = 1

' Recherche des dates
Do While a <> ""
    a = Cells(j, 7).Value
    j = j + 1
Loop
j = j - 2
    
' Recherche des valeurs pour les tag
For f = 22 To 38
    Do While b <> ""
        b = Cells(i, f).Value
        i = i + 1
    Loop
    i = i - 2
    
    If i < 8 Then
        i = 8
    End If

    If i = j Then MsgBox ("Pas de mise à jour à effectuer")

    If i < j Then
        For k = i + 1 To j
            sTime = Cells(k, 7).Value
            sTagname = Cells(5, f).Value
            macroResult = Application.Run("PITimeDat", sTagname, sTime, sServer)
            Cells(k, f).Value = macroResult
            If Cells(k, f).Value = "No Data" Then
                Cells(k, f).Value = ""
            End If
        Next
    End If

    If i > j Then MsgBox ("Il manque des dates")

Next f
        
Ok = MsgBox("opération terminée", vbOKOnly, "Recup PI")

End Sub