Wire tool and stroke in vbulletin?

[Antorr]

Hi, im using vbulletin 4.0.7 and i want use wire tool and stroke (its normal symbol in my language), but, when i write any phrase with wire tool or stroke and give save i have then only part of word.
For example Podnikání -> Podnik
Its posible change configuration to use this symbols? My language is Czech (cze, cs)