Create a macro (module?) that activates in my userform code?

Is there a way I can make :

    Dim MyDate, MyDay
    MyDate = Worksheets("Calc").Range("B1").Value
    MyDay = Day(MyDate)

Sit in a module named as a macro with something I made up like "Sub RowSelector()"

Sub RowSelector()
    Dim MyDate, MyDay
    MyDate = Worksheets("Calc").Range("B1").Value
    MyDay = Day(MyDate)
End Sub

and then call that macro to activate when I need it? So Instead of :

Private Sub TextBox5_Change()
    Dim MyDate, MyDay
    MyDate = Worksheets("Calc").Range("B1").Value
    MyDay = Day(MyDate)
        Range("E" & MyDay).Value = Me.TextBox5.Value
End Sub

I would like have:

Private Sub TextBox5_Change()
      Execute RowSelector      'I have no idea but just for example of what i need.
        Range("E" & MyDay).Value = Me.TextBox5.Value
End Sub

I am asking not only for this, but I have another set of instructions much larger that I need to be able to call in the same way.
I could probably handle the bulk thsi current method is causing me here, but my other code I need to call repeatedly would be huge.

Hello Bafa,

Here is how...

'Place this in the General Declarations section of the UserForm
Sub RowSelector(ByVal NewValue As Variant)

    Dim MyDate, MyDay

      MyDate = Worksheets("Calc").Range("B1").Value
      MyDay = Day(MyDate)

        Range("E" & MyDay).Value = NewValue

End Sub

'TextBox5 event code
Private Sub TextBox5_Change()
    RowSelector TextBox5.Value
End Sub

Sincerely,
Leith Ross