Replace Special Char from string for "table input step" kettle transformation

Some requirement i faced, to write dynamic SQL script for kettle transformation. SQL scripts are generally written in "table input step" and "SQL script" steps.

Observation i have made with two different version of data integration tool (kettle by pentaho) with 4.4 and 6.0.

Version 4.4
When we wrote some SQL script in transformation (table input step) , and if we open the saved transformation in notepad, i observed that the SQL script was in same format enclosed with html tags.

Version 5.4 and above (my observation, version are not accurate)
When i wrote some SQL script in transformation and i open the transformation in notepad, observed that the SQL script written in Spoon (developers mode), now has been in changed format. i seen that the special chars used in SQL script has been changed to some numbers.

I have listed out some special char conversions, as in below image:

Now the main task is how i can replace all above char in incoming String from any source.

Nested replace function will not work here, because replacing string contains itself special chars.

So i created own function, which will process each char of incoming string.

To see the function please refer to below link

Function to process each character of String [SQL server]