I want to know how to do or simulate a

where fieldname1 in("opt1","opt2","opt3")

but with a varchar parameters

so in the stored proc, i want a things like that:

select fielname1,fieldname2
where fieldname1 in (:paramstring)

the ':' seem to generate an error, cause it's not "" and the
operator 'IN' want ("something") with the quote(")
how you do that??