Concatenating after running a Macro.

I've run each of four sheets,in a workbook, through a
Macro (on VBA), to convert the data into a space-
delimited format. Each sheet has a different space
delimitation, that's why the data wasn't processed all
on one sheet. Now, I want to concatenate the four
*.prn files into one *.prn file, so the file can be
transmitted as one file. Each record has to appear in
a specific order; (record a,record b,record c, etc).

Can I do this, or must I concatenate first, then run
the Macro? What steps should I take?