Query filter-matching special chars.

Hi, 

I'm working on some application in TWX where I would like to have filter in mashup.

Currently it is working like= Search_string is found in infotable (e.g. BCD in ABCDE string)

But, our users will also use local language string like e.g. BČD (in slovak language).

How could I achieve that I can only use search string like BCD and I will get a result from BČD? 

Original table:

Table with search string = ABC

My current settings for filter in Service:

"filters":[
{
"type": "LIKE","fieldName": "Class","value": "%"+search_string+"%"
},

Thanks