Write XProc code for my workflow app-reg

Dear Members !!!
 I writing a xproc workflow code for my XRX application ... this workflow having three level to verify the user.. but i completed the entire application with XForms REST and XQuery Strcuture .. the problem s , now , i need to modify the entire structure with XProc pipeline language ... i don't know where to start and how to compile ... Pls give the suggession where to start and how to start -- with any one of the XProc engine (Calabash , exist-db xproc module etc...)

thanks and regards 

Rajamani Marimuthu
Junior Research Fellow-JRF
NIC -Open Technology Centre
Rajaji Bhavan
Besant Nagar,
Chennai - 90
Cell : 9791125383