Well, your question is quite generic... More details could have helped
us helping you...
1. Install the XMPie linear barcode font kit on your workstation (and
server). Please notice that XMPie released a new barcode font kit for
version 4.6.
2. In the XMPie palette in InDesign (considering that your application
already exists), define a new text ADOR
3. In the "Edit Rule" page for this ADOR, check "Advanced functions",
then select the appropriate barcode function: your Text ADOR will
automatically changed to "Text & Style", and the appropriate style is
automatically set to use the appropriate XMPie barcode font.
4. Complete your barcode function call, by concatenating several
fields if needed.
5. Create a new text block in InDesign, and insert your new ADOR in
it.
Notice: should the XMPie function encode a character string with would
include the quote character (") for any bar, don't forget to disable
the quotes management in the InDesign Preferences, else your barcode "
characters would be changed to typographic quotes (<< or >>), thus
generating the wrong barcode.