It's faster to enumerate a collection with the For each...Next statetment:
Dim c As Class1
For Each c In Col
'Code...
Next
Dim fldField As ADODB.Field
For Each fldField In rsTemp
'Code...
Next
Dim LI As ListItem
For Each LI In ListView1.ListItems
'Code...
Next
To find out the index while enumerating, use a variable:
Dim c As Class1
Dim Index as long
For Each c In Col
Index= Index + 1
'Code...
Next
Or, for zero based collections:
Dim c As Class1
Dim Index as long
For Each c In Col
'Code...
Index= Index + 1
Next