IDOC to File

Hi Experts,

I am working on to IDOC To file interface...I need to generate 3 files based on the Report_type field in an idoc...

there are many report_types(R1, R2....R10) fields in the idoc...but i need to get the it respective Pricing values only from R3, R6 and R9 and populate and generate 3 separate files...

Can someone please help me how can i achieve this.

Thanks