File content conversion

Hi friends/Experts,

I am doing a file to IDOC Scenario where format my flat file is in :

Header:"FIELD1" "FIELD2" "FIELD3" "FIELD4"

Item1:"FIELD1"

"FIELD2"

"FIELD3"

"FIELD4"

"FIELD5"

Item2::"FIELD1"

"FIELD2"

"FIELD3"

"FIELD4"

"FIELD5"

Item3::"FIELD1"

"FIELD2"

"FIELD3"

"FIELD4"

"FIELD5"

Item4::"FIELD1"

"FIELD2"

"FIELD3"

"FIELD4"

"FIELD5"

I am getting struggled in my content conversion.Could you please help me how to convert this in the sender communication channel.

Thanks in advance,

Kalam.