Range as Parameter in Function Declaration

A simple question that google yields no assistance on.

I have a formula that hides rows within a range for a sheet.

Sub HideRows(RStart As Range, REnd As Range)
   Range(RStart, REnd).Select
   'Code to Hide Rows, does not matter
   ...
End Sub

I am clearly doing something wrong because I am having troubling calling the function.

For instance Call HideRows("A1", "A20) does not work

Also, changing the HideRows formula to have one parameter does not work for me

Sub HideRows(RStart As Range)
   Range(RStart).Select
   'Code to Hide Rows, does not matter
   ...
End Sub

Call HideRows("A1:A20")

Any guidance would be appreciated as I am not sure how to use parameters