IDOC Message Mapping

In File to IDOC senario,

I have a Mapping Condition like this:

IF A02 = 'X' map 'VER ' + A05 + '- ACCEPTED'
IF A02 = 'Y' map 'REJECTED'
IF A02 = 'Z' map 'VER ' + A05 + ' -  EXCEPTIONS'
IF A02 = 'A' map 'VER ' + A05 + ' -  HOLD'
IF A02 = '' map 'VER ' + A05 + ' -  ACK'

Note: Trim any leading zeros in A05 while forming string. If A05 is not available, then use prefix 'VER UNK - '.

Sourcefield : A02

Target field : E1EDK02 - BELNR

                     QUALF = 002

I am unable to map it correctly.

Give some mapping example and Tips.

Explain this.