Invoke function from custom helper in lang file

[eluser]inst[/eluser]
Hi all,
I have a weird problem with a language file. When I call "built in" functions like anchor(), safe_mailto() etc they are working, but if I call function from custom helper i got call to undefined function.
Is it possible to you my own functions in language file ?

[eluser]Clooner[/eluser]
Who knows? What did you try, and what did you get? You have some code?

[eluser]inst[/eluser]
My mistake. I forgot to autoload my helper file.