How to get last and first values from attribute in XSLT

I want to get the first and last values from an attribute value,

(ie):

<entry aid:table="cell" aid:ccols="1" aid:theader="" aid5:cellstyle="chart_cellformat_headline" rowsep="1" colsep="1" align="center" spanname="col234"><para><emphasis aid:cstyle="bold" role="bold">Habla real</emphasis></para></entry>

from the above tag I want to get the values 2 and 4 from spanname="col234" attribute, I didnt tried any, Im new to XSLT

Please anybody share any ideas

Thanks in advance!