Sub MySolver()
    Dim wbSolv As Workbook
    
    'подключаем "Поиск решений"
    On Error Resume Next
    Set wbSolv = Workbooks("Solver.xla")
    
    On Error GoTo EH
    If wbSolv Is Nothing Then
        Set wbSolv = Workbooks.Open(ThisWorkbook.Path & "\Solver.xla")
    End If

    'Инициализируем
    Application.Run "Solver.xla!Auto_Open"
    Application.Run "Solver.xla!SolverReset"
    
    'Данные для расчета
    Application.Run "Solver.xla!SolverOk", "$E$4",  3 ,  0 , "$G$7:$G$9"
    Application.Run "Solver.xla!SolverAdd", "$G$7",  1 , "$G$8"
    'Application.Run "Solver.xla!SolverAdd", "$G$8", 3, "$G$9"
    Application.Run "Solver.xla!SolverSolve"
    
    Exit Sub
EH:
    MsgBox Err.Source & "~" & Err.Description
End Sub