Although I would still like to know if the above is possible, the solution I have come up with is to not have a linked table to an XLSX file, but to have a static table.
This way, Access is able to easily add a new record to it.
Once this is done (for however many records there are) it will export this to the network (As both a backup and if other people copy the frontend locally).
'NewWord set to false after Dim'ing it as Boolean, then if a new word is found, set to true
If NewWord = True Then
'delete spreadsheet
Kill "Z:\Words.xlsx"
'create a new one, based on the table
DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel12Xml, "Senti", "Z:\Words.xlsx"
End If
The kill command is to delete the existing xslx file at the location, as it doesn't seem to override if the file exists.
Also, if the file on the network path is updated, I have a button elsewhere that will update the database with this.
DoCmd.DeleteObject acTable, "Senti"
DoCmd.TransferSpreadsheet acImport, acSpreadsheetTypeExcel12Xml, "Senti", "Y:\Words.xlsx", True
Hope that helps anyone else with a similar issue