Nested internal table

Hi Sap gurus,

Am in a bit of a fix right now..............

I have got an internal table in the format - Doknr and a nested table.....such that for every doknr multiple records may exist in the nested table.............

it is if the format:::: begin of ty_nested, doknr type doknr, include structure zstruct, types: end of ty_nested.

now i want to append data into this particular table so that whenever a particuar doknr comes up all the corresponding data fro the doknr should go into the nested table

it should be of the format........ doknr->nestedtable. '/' denotes the multiple records that exist in the nested table

10 2/3/4

20 1/3

30 3/4/5

any help will be appreciated......