Obviously my code does not work

I find that your code doesn't provide much safety net, so you have a hard time seeing where it fails. for instance, you split on tabs. Can you be sure, that the fields will really be separated by tab characters always (and not sometimes by spaces)? Are you sure that a line can't have embedded spaces? And if your line does not satisfy the regexp pattern, is it OK to silently ignore that line, or should there be printed an error message?

Further, your program contains a few variables (for instance, $from_tg) which are never initialized, so I guess you didn't provide the whole code.

And, are you really using strict and warnings in your original code?