Bulk merge - fax multiple customer invoices to one recipient?

I need to fax invoices for many different customers to one recipient at one time.  Our sales rep requires that a copy of each invoice that was billed during the previous month be faxed to her once a month with her commission statement.  We have created a saved search to find the invoices, but the way we've been faxing them (by editing each one, copying the rep's fax number under messages and clicking 'save') is quite tedious when there are 40-50 invoices per month.  We do not have the advanced commissions module - I am not sure if this is