internal table update

hi

i have two internal tables

1 isthe internal table treturn from bapi_goodsmovmt which has error messages

i need to send this error msgs to tmsg table of the function module SO_NEW_DOCUMENT_ATT_SEND_API1

but when i send the msgs to tmsg it should deffrentiate the msgs for diffrent items

for example

item 1

list all the errors

item2

list all the errors

because there may be many items for a po

can any one suggest me how to do