Best Way To Write This

Hi,
I have to implement a search functionality. In the various filters for the search, Store Number is one such filter.
The user should be able to enter range values for store numbers.
Like 1500-1600. So this should filter for all the stores between 1500 and 1600.
Similarly, all these also should be valid.
1550,1600
1550
1550 - 1580,6000,8000
etc.
I have function which identifies the commas or dashes and seperates out the store number and returns a string like
Stores.Storenumber in(1555,1600)
Store.StoreNumber between 1555 and 1600 etc...
i generate a sql at run time and append this piece and then execute the sql.
I have one of the query below.

declare @strQuery varchar(max)
declare @strConcat varchar(10)
declare @strAppend varchar(max)
set @strAppend=''
set @StrConcat ='And '

if @IsAdmin is null-- Not a Admin
set @StoreId =(select StoreNumber from Stores where Store_Id = @StoreId)

set @strQuery='
Select
(Select StoreNumber from Stores where Store_id=d.DestinationId) as StoreNumber,
CartonNumber,
ActualReceiptDate as [Scan Date],
isnull(Sum(QtyShipped),0) as [Total Units],
b.BatchNumber
from
Carton c
left outer join
CartonDetail Cd on Cd.Carton_Id = c.Carton_ID
inner join Batch b on b.General_Id = c.Carton_Id and b.BatchType=''Warehouse'' and b.TranTable=''Carton''
inner join Document d on d.Document_ID = c.document_Id
inner join Stores st on st.Store_ID = d.SourceID and st.StoreType =5
inner join Stores on Stores.Store_ID = d.DestinationID
inner join Codelist cl on cl.Codelist_Id = c.CartonStatus_ID
inner join Codes on Codes.Code_ID = cl.Code_id and Codes.CodeType=''Cartons Status Code''
where not c.cartonNumber is null '

if not (@StoreId) is null
begin
set @strAppend = @strConcat + '(' + dbo.DecodeStoreNo(@StoreId) + ')'
End

if not (@DateFrom) is null and not (@DateTo) is null
begin
set @strAppend = @strAppend + @strConcat + '(convert(varchar(50),c.ActualReceiptDate,101) between ''' + @DateFrom + ''' and ''' + @DateTo + ''')'
End

if not (@CartonNumber) is null
Begin
set @strAppend = @strAppend + @strConcat + '(c.CartonNumber = ''' + cast(@CartonNumber as varchar) + ''')'
End

if not (@Status) is null
Begin
set @strAppend = @strAppend + @strConcat + '(cl.Codevalue = ''' + @Status + ''')'
End


set @strAppend = @strAppend + ' group by
d.DestinationId,CartonNumber , ActualReceiptDate , b.batchnumber
order by ActualReceiptDate'

set @strQuery = @strQuery +@strAppend
execute(@strQuery)
This query takes time, if there a little over 1000 records.
I wanted to know, if there is any way to optimize this query? or any other way in which the above can be accomplished.

I hope i was able to explain my query fairly. Please let me know otherwise.

Thanks
Renu.