Need regular expressions to separate files

1) result from workflow is file names separated with a ";"

example:

if there is one file:
test.xls
if there are two files:
bad.txt;good.xls
if there are three files:
me.ppt;you.xls;we.txt


i guess i need several regular expressions
to break out and to identify each of those file names
not knowing how many file names
i will place a limit of 5 file names

1) need a regular expression that would give me just file name 2 with and with out additional files
2) need a regular expression that would give me just file name 3 with and with out additional files
3) need a regular expression that would give me just file name 4 with and with out additional files
4) need a regular expression that would give me just file name 5


thanks you