If you want to keep the cheque stub at the bottom of the page and the invoice/voucher stub at the top; and assuming you're using a Word RTF template; do the following:
(1) Define the cheque stub using a <?template:template_name?> decalaration. This will allow you to print the cheque stub using a <?call-template:template_name?> directive.
(2) Now, the trick is to define your RTF template as having different headers and footers on the 1st page. Use the /File/Page Setup Word command to change the layout to have a different 1st page. This should allow you to have a different set of header and footer on the 1st page.
(3) Putting it all together... You can then use the <?call-template?> directive in the 1st page's footer to print the cheque stub. This will ensure that the cheque stub always appears at the bottom of the page, at the same fixed area - which is the page footer.
Any vouchers/invoices will spill into the succeeding pages.