Multiple Idocs

Hi Experts,

We are implementing Idoc to File in SAP 7.4.Our file is having Header transaction...like 16 one by one in the file.Client is identified to use 6 Idocs to map the entire file and it should be a single file and don't want to do customization of idoc

My question is how can we import the 6 idocs in message mapping to achieve this logic to get all the data in one file.Is there any logic to do here without any customization of idocs.Please give me your valuable inputs.

Any help would be appreciated.

Regards,

Shaik