It depends how the comboBox is populated. If it is populated from a named
range on the worksheet (say, it is called MyRange) then you could use
something like:

MyRange.offset (cboMyBox.ListIndex,0)

ListIndex gives the position in the list of the selected  item starting from 0.
This assumes the range is a vertical range.

Suppose I have a user form with a combo  box. The combo box  is populated from a
data range on the worksheet. It's a database with records. I want for exemple to
edit a certain record which I select with the combo box. To be able to edit a
certain record I have to activate  the row where that record is. If for exemple
from the user form, I select an item  from the combo box and I put a button named
"Edit this record" how to I make the form to open that record, that is I have
somehow make select that row by means of a code. Did you catch what I mean? For
instance, it's a database with birthdates. Suppose I enter a new record and
pressed the OK button. I added a new record to my database which is on a
worksheet named DataSource. Lately I mentioned a mistake in a record and I want
to edit that record. I select the record with the combo and press the button
"Edit this record". Now you see what I mean?

Try

MyRange.offset (cboMyBox.ListIndex ,0).activate

You would put this in the click event of the edit button

I did that a while ago using a userform with textboxes. Each textbox
was linked to one of the different columns on the worksheet. I used a
macro to search for a record then set that cell  to active and used :



Range("E" & ActiveCell.row)=commentstextbox.text



I used similar lines of code to populate the textboxes on the userform
and then I was able to modify them as I desired. Afterwords I used a
command button to use another macro to update that record to what was in
the userform. I would give more help with specific code but the form
was very large and had a lot of code for a lot of other things in there
as well.

Look what I did, but the code fails.

Private Sub cmdEdit_Click()
Manager.Offset(lstData.ListIndex, 0).Activate
End Sub

Private Sub UserForm_Initialize()
Dim lRow As Range
Dim ws As Worksheet
Set ws = Worksheets("DataSource")
For Each lRow In ws.Range("Manager")
With Me.lstData
.AddItem lRow.Value
.List(.ListCount - 1, 1) = lRow.Offset(0, 1).Value
End With
Next lRow
End Sub

Try

Worksheets("DataSource").Range("Manager").Offset(lstData.ListIndex,
0).Activate

While you are in the editor click Debug/CompileVBA Project. If this throws
errors you need to correct them. Then try to run it and let me know what
happens. Don't say "It Fails". I need to know what error message there is or
if nothing at all happens. When you look at the spreadsheet what cell  is
active?

Actually I need a line of code which will link the active cell  on the worksheet
with the selected  item from the list box.

but to tell you the truth i didn't quite understand. David
sent me a line of code which would help, but I don't know why it fails. Maybe
you can help. The bold line should active the row in the worksheet with the item
selected in the listbox. I don't know why it generates error.

Private Sub cmdEdit_Click()
Manager.Offset(lstData.ListIndex, 0).Activate
End Sub

Private Sub UserForm_Initialize()
Dim lRow As Range
Dim ws As Worksheet
Set ws = Worksheets("DataSource")
For Each lRow In ws.Range("Manager")
With Me.lstData
.AddItem lRow.Value
.List(.ListCount - 1, 1) = lRow.Offset(0, 1).Value
End With
Next lRow
End Sub

it works perfectly, except it select the range as well. In
fact, it doesn't bother me.