language translation using variable

dear all,

i need to have language translation to user entered text(dynamic property).

mean to say in my custom widget i provide one dynamic property to select language from list of languages and one more dynamic property to enter text.

say for example user enters some text and selects language "dutch" that particular string should be translated to dutch.

i have achieved language translation of static string ( mean to say i have directly entered text in tr() with out dynamic property to enter text).

so can some one suggest me how do i achieve the same with dynamic property ( dynamic property with respect to text). "is there any way to set language for strings not enclosed in tr()"

thanks in advance for any help.