Changing Ranges In A Macro?

Code:

Sub appointment_nieuw()
With CreateObject("Outlook.Application").CreateItem(1)
.Subject = Range("C3")
.Start = DateValue(Range("A3")) + TimeValue(Range("B3"))
.Duration = 0
.Location = Range("D3")
Dim cell As Range
For Each cell In Range("F2:H2")
.body = .body & Space(2) & cell
Next
.Save
End With
End Sub

I have this macro that works great, but every time I have a different appointment. I have to go into VB editor and change the ranges for the subject, datevalue, timevalue, location and body.

Can I get a text box (or something better) to pop up and I enter the ranges for the 5 in it and have it change in the macro?