It's probably better to have the following situation:
a. the template isn't attached to the data source
b. an AutoNew macro in the template connects new documents created from the
template to the data source.

e.g. something like the following for an Excel file with a Sheet called
"mysheet"
Sub AutoNew()

Dim strPathName As String
Dim strQuery As String

' Put the pathname of your Excel .xls
strpathName = "c:\myworkbooks\mywb.xls"

' Construct the Query - you may also need WHERE and ORDER BY
' clauses for filtering and sorting

strQuery = _
 "SELECT * FROM `mysheet$`"

' The following should be enough in Word 2003
' If you do not need WHERE clauses etc. you
' can delete the SQLStatement line

 ActiveDocument.MailMerge.OpenDataSource _
   Name:=strPathName, _
   SQLStatement:=strQuery

' Set the merge type you want
 ActiveDocument.MailMerge.MainDocumentType = wdFormLetters

' optionally set the destination you want
 ActiveDocument.MailMerge.Destination = wdSendToNewDocument

End Sub

If you aren't in a position to use macros, I'd say the simplest approach is
probably to do the same thing, but connect manually each time, which is
tedious, but will probably do the trick. It may be worth veryifying whether
or not the resultant document is trying to open the data source because /it/
has a data source attached, or because its template has. If it's only
because the template has, then that suggests that you have already
distributed the template to your recipients. Otherwise, if /their/ version
of the template didn't have a data source attached, the document would not
try to open a data source, IYSWIM. (I'd research this better but it's not
going to happen this evening).

Peter Jamieson