Issue in conversion ABAP to java mapping during PI upgrade

Hi All,

We are upgrading one interface from ABAP mapping to Graphical/Java mapping in PI upgrade.(7.1 dual stack to 7.4 version)

In ABAP mapping there is character conversion like below.

  encoding    = '1164'

      replacement = '?'

We want to implement the same functionality either through Java or graphical mapping . But we are not sure what are the range  of characters that need to be converted to '?' and also what is the most optimized way to achieve this functionality.

Below are few sample of characters coming in the file:

б,л,к,У,М,л,и,о,ф..etc