Dynamic length possible for data in oracle etext

Hi,
Thanks for your help

<LEVEL>

OutboundPaymentInstruction

<POSITION>

<LENGTH>

<FORMAT>

<PAD>

<DATA>

 

35

23

Alpha

 

(ReferenceNumber)

Here length is define 23 but my reference number comes in 10 charactes
Now in Format  output its display like
Invoice num :TEST687254              
                     012345678901234567890123
13 characters extra space displayed how can we truncate this space.


Thanks