integers, date in punbb1.3

hello,
I have translated punbb 1.2.x to my language Bangla (Bengali). Like most other software, all strings were in Bangla except the numbers, date etc. For that I have used a mod to convert string in Bangla. Suppose, in forum homepage there were forum name, topics, posts, last posted by in english.

i hacked the codes and showed numbers of topics, posts in Bangla.

if the code was like:

echo $num_topics;

i have changed it to:
echo convert2bn($num_topics);

the convert2bn() function takes care of converting english strings to Bangla.

But I am worried about 1.3. How these issues are handled there? have I still need to hack each file manually?  or i need to make a extension to do all such. I think, in extension, it will be too long. but if there is option in language file, that will be nice.

suppose:
$int1='১';
$int2='২';

or it may be in array. then it will be much easier to translate us.

thanks in advance!