Split and Concatenate data

I have a group of fixed width text files that come in daily. These files contain thousands of records each. Each record has an (01)Header, (02)Detail 1 and (03)Detail 2. I would like to import each file using an SSIS package. I would like to be able to concatenate Header+Detail 1+Detail 2 into one long string. I believe I can do this with a script task but I have little to no C# experience. Please help.

01MR0120150103033831785 20150105DD 20141202011046862

02PM2014110620141201 004868971 T1A

03KA00000000050000TDEN0000000050000 2014110620141201

01MR0120150103033831922 20150105DD 20141202011047922

02PM2014102920141201 004483874 T1A

03KA00000000130000TDEN0000000130000 2014102920141201

01MR0120150103033833730 20150105DD 20141106030858272

02PM2014092620141105 004812213 T1A

03KA00000000070000TDEN0000000070000 2014092620141105