RE: String manipulation in XSLT

I have a string of the form babc.def.ghib (java namespace ) where babc.defb is the package name and bghib is the class name.
I need to extract these two from the complete string : babc.def.ghibB  -------b babc.defbB  + bghib

In java this would take about 1-2 lines of code, but in XSLT I cannot figure out a way to do it without writing tons of code.
Why is the support for string manipulation and regular expressions non-existent in XSLT, when XML is all about text ( more than java etc.. )??

Ibm constantly frustrated by trying to write little templates to do these simple things like splitting a string etc.

TIA