for each i as (object here) or for each i in (form here)

[Ultimasnake]

i cant seem to get either of these two vb6 commands correctly

dim i as popbox
for each i in frmmain ' where frmmain is the form i am on
  'do something with object here
next i
 
 
' and
dim i as object
for each i as popbox ' where popbox is a usercontroll in the current form
  'do something with object here
next i

so what is the proper Vb.net way to loop through a certain kind of object and do something with it?