Inbound Idoc processing

hi folks,

I got one requirement to upload the data... I get the data in the form of flat files in application server. I have to take that file from the application server, process the data and upload that data into sap system.....

Actually they asked to use the LSMW with FIDCCP02 idoc method to upload the data but they changed the spec and asked me to write a program to upload the data in the same fashion ( because it includes the data for two applications one is open AR items and so on...) can anyone guide me how to write the code for this.....

Thanks a lot for the anticipation

SRI