This one is for Lopardo (because he said on IRC he was too lazy to translate a formula into spanish
)
I think it should be this in Spanish:
code:
=EXTRAE(A1;ENCONTRAR("*";SUSTITUIR("\" & A1;"\";"*";LARGO(A1)-LARGO(SUSTITUIR(A1;"\";""))+1));LARGO(A1))
Note: this isn't exactly the formula you've found, but it is based upon it (read: fixed). The formula you've found would have given an error if no path was given.
PS: to translate functions, you can use this page as a guideline:
http://dolf.trieschnigg.nl/excel/excel.html