Looping Thorough A Table To Get Code List

Assume there is a table called Item:

and fields Itemcode Customercode

now a customer may have one or many items(itemcode)

Now the issues are, Customercode can be zero or a code value.

NOw i want to put a do while loop to get all the records as comma seperated format

TempItemcodest=0
select * from Itemtable where customercode=customervalue
Do while not Rs.eof
TempItemcodest=TempItemcodest & "," & rs.fields("Itemcode")
rs.movenext
loop

TempItemcodest=TempItemcodest & "0"

so i am adding a zero at the begging and end to have the commas seperated properly.

is there any better way to do this?