Not sure if I understood it correctly but here is a suggestion:
Implement in your CL the commands
DCL VAR(&NAME) TYPE(*CHAR) LEN(14)
DCL VAR(&DATE) TYPE(*CHAR) LEN(13)
DCL VAR(&RENAME) TYPE(*CHAR) LEN(10)
RTVMBRD FILE(SRCLIB/SRCFILE) MBR(&MBRNAME) CRTDATE(&DATE)
CHGVAR VAR(&NAME) VALUE(‘F’ *TCAT &DATE)
CRTDTAARA DTAARA(QTEMP/NAME) TYPE(*CHAR) LEN(14)
CHGDTAARA DTAARA(QTEMP/NAME) VALUE(&NAME)
CHGDTAARA DTAARA(QTEMP/NAME (3 1)) VALUE(‘F’)
RTVDTAARA DTAARA(QTEMP/NAME (3 9)) RTNVAR(&RENAME)
After that you are allowed to determine ow you will work with the file name (F+date+time). You can write an RPG to build the FTP input command receiving &RENAME as the variable name, or you can rename the file member using RNMM command, or you can use CPYTOIMPF to convert the file in a stream file with the &RENAME variable and them FTP the file.
Hope it can help a little bit.
If the folder is Located in QDLS you have to know that the Name of the document is limited to 8 characters and a 3 character extension.