I try to name a cell Z210 but the name doesn’t stick.

I am sorry, Z210 is not a legal name since Excel thinks it is column Z row 210. You can use Z210x.

Can I change the label names on the HTML form without corrupting the calculating formula?

You cannot change the id or name directly on the web page. They are used in the calculation part. But there is a solution:

If you name the cells in Excel using Insert-Name-Define, and these names start with a letter, and only contains letters, digits and _, then these names will be used in the form.

Can I name ranges of cells?

Yes, but SpreadsheetConverter will not use them in the email with the submitted data. You have to name each individual cells.

I need to name the cells with item id. Is there a quick way of doing that?

This little macro will name the cell according to its contents.

A simple use is to fill the input cells with the article number (with an additional leading letter), mark the range, and run the function.

'make a name out of each text in the cell and remove the cell
'illegal chars are replaced by underscore
Sub MakeNamesFromSelection()
     Dim theCell As Range
     For Each theCell In Selection
         Dim sValue As String
         sValue = theCell.Value2
         sValue = Replace(sValue, "-", "_") 'todo: many more!
         sValue = Replace(sValue, "/", "_") 'todo: many more!
         If sValue <> "" Then
         ActiveWorkbook.Names.Add Name:=sValue, RefersToR1C1:=theCell
         End If
         theCell.Clear
     Next
End Sub

Replace requires Excel 2000 or later.

Is there any way I can control the Name attribute of an input field?

Name the cells in Excel using the little box up to the left.

The name must start with a letter. The rest can be letter, digit and _.

These names will be used as id.