Select importtable.custext, line2.custext, line3.custext into customertable
from (importtable
inner join importtable line2
on importtable.id = line2.id+1)
inner join importtable line3
on importtable.id = line3.id+2
where (importtable.id = 1) or (importtable.id mod 3 =0)