VBA - Define Selection using cell reference

Yes, you can do that. See the attached example (I'm putting the values in F2 for the example)

Option Explicit
Sub pasteChoosenRows()
Dim rowsToUse As Long
Dim source As Range, destination As Range


'Adjust these to the real sheet'
rowsToUse = ActiveSheet.Range("F1").Value
Set source = ActiveSheet.Range("A2")
Set destination = ActiveSheet.Range("F2")

'Align the values'

destination.Resize(rowsToUse, source.End(xlToRight).Column - source.Column + 1).Value = _
source.Resize(rowsToUse, source.End(xlToRight).Column - source.Column + 1).Value

End Sub