How can I properly make typewrite effect for multiline Right to Left Text with a cursor?

Have anyone worked with make typewrite animation with Arabic or Hebrew text?

The issue here is if I use one line letter I can make the cursor symbol at it's last position by placing the cursor before the actual text in the expression. For Example.

Source Arabic text :
اللغة العربية

Expression:
"_" + text.sourceText;

Result:
اللغة العربية_

It's not a problem at all for single line arabic text. But If I try it on multi line arabic text

Source :
اللغة
العربية
Expression :
"_"+text.sourceText;

Result:
اللغة_
العربية

Same thing happens for Hebrew.

So how can I make the cursor always follow the last letter of the text even if it's a multi line right to left language?