Setting outfile with (brackets)

I have a file that comes in as 20081002_invoices.txt and needs to go out as
invoices(20081002).xls When ran this file should have three seperate fields as follows:

column1 column2 column3
data1 data2 data3

when i run the script it produces the invoices(20081002).xls but moves the three fields into one column in excel?

column1
data1,data2,data3

I have tried numerous ways and it looks like it is the () it does not like, unfortunately that is how it needs to go out.

any help??

Can you show us what your script does so far? Kind of hard to think about a problem without seeing what you have done so far.