Trying to include the "Hide details" command in a macro but with variables

Dim Ctr1 As Variant
Dim Ctr2 As Variant

Ctr1 = 8
Ctr2 = 23

Rows(Ctr1 & ":" & Ctr2).Select
worksSelection.Rows.Group
ExecuteExcel4Macro "SHOW.DETAIL(1,23,FALSE,,7)" - works

ExecuteExcel4Macro "SHOW.DETAIL(1,Ctr2,FALSE,,Ctr1 - 1)" - does not work
Get a Run-time error '1004' -You've entered too many arguments for this
equation.

Any ideas?