Dear Amol
I did never tried to use this type of functionality in SDS distribution process. The issue is like this:
you have a "status net" in CVD1 (report distrbution process). Now to enter something (manually ??) (as with user entries) you need to stop the SDS distribution process on a specific status (which one? bundle ??) to do so and then (after entering the data) you need to process to the next step (manually). Therefore we can not "talk" about an automatic process any more (and I have real doubt that you would like to really use it like that). Clearly if the data is stored there could be a problem coming up with "subsequent shipment" as well because the distrbution process will use the same status net and therefore the process would e.g. stop in "bundle" (even if there is no need to "reedit" the data (as mentioned: the data could be stored as an "append" to CVD1 data structures).
This was one reason why, may be, i "misinterpret" what you are looking for (are we talking really about a manual entry???).
It is possible to enhance CVD1 to store more data as part of the process in data base (this is a "normal" parameter symbol (that was the reason why i included the "expansion" topic): now if you do not want to maintain something "manually" but you could specify clearly location of data etc. and the data is not part of EHS you need to prepare a suitable parameter symbol as part of layout to fetch the data. Here you need not so "stop" CVD1.
Check may be:
http://scn.sap.com/thread/3380754
Here discussion is ongoing regarding data to be printed in coversheet
GLm is "different" (can be) in comparison to other WWI processes (including report distribution process). Therefore you can not discuss "expansion time" without knowing the exact set up of GLM.
Hope I did catch now your demand. To make it short: in report distribution process you have two types of document: Raw report and coversheets. An "user entry symbol" can be mapped in my opinion to a "parameter symbol"; therefore data is there only in final report and not raw report.
C.B.
PS:
may be:
http://help.sap.com/saphelp_dimp50/helpdata/en/74/9f745eab8411d5993700508b6b8b11/content.htm
could be of interest
as well as:
http://www.consolut.com/en/s/sap-ides-access/d/s/doc/YY-IHS_MD_SYMBOL_FIELD
http://www.consolut.com/en/s/sap-ides-access/d/s/doc/YY-EHS_SR_230_10_5
or
http://help.sap.com/saphelp_erp60_sp/helpdata/en/b3/75a580b0b411d5993800508b6b8b11/content.htm