Sub SumPosValOfMatrix()
    matrixA = CreateMatrix(10, 20)
    matrixB = CreateMatrix(15, 10)

    Dim i As Integer, j As Integer
    Dim sum As Single
    sum = 0

    For i = 1 To 10 'string_count
        For j = 1 To 20 'column_count
        If matrixA(i, j) > 0 Then
        sum = sum + matrixA(i, j)
        End If
        Next j
        MsgBox ("matrixA: " & vbCrLf & " Сумма положительных чисел в строке " & i & ": " & sum)
        'обнуляем сумму
        sum = 0
    Next i

    For i = 1 To 15 'string_count
        For j = 1 To 10 'column_count
        If matrixB(i, j) > 0 Then
        sum = sum + matrixB(i, j)
        End If
        Next j
        MsgBox ("matrixB: " & vbCrLf & " Сумма положительных чисел в строке " & i & ": " & sum)
        'обнуляем сумму
        sum = 0
    Next i


End Sub

Public Function CreateMatrix(string_count As Integer, column_count As Integer)
    Dim i As Integer, j As Integer
    ReDim matrix(1 To string_count, 1 To column_count) As Single
    For i = 1 To string_count
            For j = 1 To column_count
            matrix(i, j) = Rnd() * 200 - 100
            Next j
        Next i
    CreateMatrix = matrix
End Function