running vba on active cell selection

hello,

i have a holiday planner that i'm working on, i have a cell range of B15:C155 the has the days start and finish B & C, i already have a calendar within the workbook but cannot seem to get it to activate when a cell within the range is selected, here is the vba for the calendar

Sub OpenCalendar()
' Displays the UserForm and calendar
' Shortcuts should be made to this procedure
    frmCalendar.Show
End Sub

Option Explicit


Private Sub Workbook_Open()
    Dim NewControl As CommandBarControl
' Assign shortcut to display calendar on SHIFT+CTRL+C
    Application.OnKey "+^{C}", "Module1.OpenCalendar"
' Add item to shortcut menu on open
    On Error Resume Next
    Application.CommandBars("Cell").Controls("Insert Date").Delete
    On Error GoTo 0
    Set NewControl = Application.CommandBars("Cell").Controls.Add
    With NewControl
        .Caption = "Insert Date"
        .OnAction = "Module1.OpenCalendar"
        .BeginGroup = True
    End With
End Sub

Private Sub Workbook_BeforeClose(Cancel As Boolean)
' Delete item from shortcut menu on close
    On Error Resume Next
    Application.CommandBars("Cell").Controls("Insert Date").Delete
End Sub

can anyone help me??

thanks reg