Auto Rename the PDF Exports to Desired Names

I have a transport PDF for making LR copies for sending to clients and drivers. How can I auto rename the export of the PDF files to these format like

LR <dispatch number> Consignee copy

LR <dispatch number> Consignor copy

LR <dispatch number> Driver copy

<dispatch number> is the number appearing in the PDF file in the LR form field. 

Auto renaming will save me time rather than manually renaming export pages. Please let me know asap.