how to transfer changes in person assignment from PS to web portal

hI

We want to transfer the person assignment data entered in Project structure (CJ20N) to a customised Web portal for Time entry

Although we are able to do this for the first time at the creation of the database in portal , but any additions / deletions done in person assignment in CJ20N are not getting transferred to web portal

Is there any way of doing this .

We are ready for doing any enhancement also in CJ20N or elsewhere , if it is available

rgds

sandeep