How to set logon parameters for crystal report with postgre

Sir, i also checked above link,but not getting any hint. Currently i have crystal reports with sql server datasource..if i changed report datasource to postgre sql then report preview correctly....but i don't want to do such working for 100+ reports...because it so much time consuming..

I want to change crystal report datasource from sql server to postgre at runtime..currently my code like this for sql server datasource connection.. and want to do modification in code for postgre sql

/// Code////