Option Explicit
Sub Main()
    Dim z(3, 3) As Integer
    Dim i As Integer
    Dim j As Integer
    Dim m As Integer
    Dim n As Integer
    Dim min As Integer
    
    z(1, 1) = 2
    z(1, 2) = 8
    z(1, 3) = -7
    z(2, 1) = 3
    z(2, 2) = 10
    z(2, 3) = -12
    z(3, 1) = 7
    z(3, 2) = 18
    z(3, 3) = 19
    min = 100
    For i = 1 To 3
        For j = 1 To 3
           If min > z(i, j) Then
             min = z(i, j)
             m = i
             n = j
            End If
           
        Next j
    Next i
    MsgBox ("Минимальный Z(" & m & ":" & n & ") = " & min)
    
End Sub