The first part is easy to do with legacy form fields, set the Order field property as a number field and check the calculate on exit check box. Insert the following where you require it using CTRL+F9 for the bracket pairs {}
{IF { Order } >=100 "Thanks" "The minimum order is 100 units"}. The fields will be calculated when you tab out of the order field when the form is protected.
The second part is much more complicated and requires the use of macros to unlock the form, insert the table and the fields it will contain and relock the form.
Frankly I would recommend the use of content controls rather than legacy form fields. For the first part use two text fields one titled Order and the other titled Response.
You can then use the following macro to establish which control has been filled and insert the required text
Code:
Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)
Dim oCC As ContentControl
Select Case ContentControl.Title
Case Is = "Order"
Set oCC = ActiveDocument.SelectContentControlsByTitle("Response").Item(1)
If ContentControl.ShowingPlaceholderText = False And IsNumeric(ContentControl.Range.Text) = True Then
If CInt(ContentControl.Range.Text) >= 100 Then
oCC.Range.Text = "Thanks"
Else
oCC.Range.Text = "The minimum order is 100 units"
End If
Else
oCC.Range.Text = ""
End If
End Select
lbl_Exit:
Exit Sub
End Sub
You can add a further Case statement to the same macro to insert a table and further content controls as appropriate when the department is selected from a dropdown list control. You can fill that list from your Excel file.
See
Insert Content Control Add-In with regard to the use of Editors and protection, converting the form to content controls and filling the list from Excel.
See attached example.