create table #workingtable (
    ControlDetailID int not null,
    LookupValue nvarchar(50) not null,
    List nvarchar(4000) null )

insert into #workingtable (ControlDetailID, LookupValue)
select
    ControlDetailID,
    LookupValue
from
    Patricks_Table
order by
    ControlDetailID,
    LookupValue

declare
    @list nvarchar(4000),
    @lastID int

select
    @list = '',
    @lastID = ''

update
    #workingtable
set
    @list = list = case
                       when @lastid <> ControlDetailID then LookupValue
                       else @list + ', ' + LookupValue
                   end,
    @lastid = ControlDetailID

select
    ControlDetailID,
    max(List) as CSV
from
    #workingtable
group by
    ControlDetailID