Convert text string to date format DDMMYYYY for LSMW

In excel date format is DD.MM.YYYY (10 characters)
In LSMW the target field has 8 characters (DDMMYYYY) or (DD.MM.YY) or (YYYYMMDD).

Code to convert the text:
Alternative 1:
BBKPF-BLDAT(6) = IMPORT_BKPF-BLDAT(6).
BBKPF-BLDAT+6(2) = IMPORT_BKPF-BLDAT+8(2).
Result: 01.10.16

Alternative 2:
BBKPF-BLDAT(2) = IMPORT_BKPF-BLDAT(2).
BBKPF-BLDAT+2(2) = IMPORT_BKPF-BLDAT+3(2).
BBKPF-BLDAT+4(4) = IMPORT_BKPF-BLDAT+6(4).
Result: 01102016

Alternative 3:
REPLACE ALL OCCURRENCES OF ‘.’ IN IMPORT_BKPF-BLDAT WITH ”.
BBKPF-BLDAT = IMPORT_BKPF-BLDAT.
Result: 01102016

Alternative 4:
concatenate main-DOC_DATE+6(4)
main-DOC_DATE+3(2)
main-DOC_DATE+0(2)
into E1BPFAPO_GEN_INFO-DOC_DATE.
Result: 20161001