Adding IdnA Converter (PHP) To Sign Up Page

I want to add Idn A Converter ( I found it here phpclasses org idna converter ) To registration page. My English is not good enough so I explained it with a photo.
Please take a look at a sec.

 

Do you realy want to use a Idn converter for this? please try to give more details!

 

Yes I want. In fact Idn converter is my opinion if it is possible I can do somethingelse.

Let me explain :

I want to allow speacial character like æ ,€ etc. so that people can sign up domains including these chars. when you sign up with the name of "æ.com" it should encode it to "xn--6ca.com" but there is some specialities when a letter comes right or left side of an IDN. For example if you try to sign up "æro.com" it will encode it to "xn--ro-0ia.com" not to "xn--6caro.com" æ ro ro is in middle not at the end.

I think it is clear now , If this explanation is not enough please let me know. Thanks