I am using:
XPATH 2.0 and XSLT 1.0 with FOP

I am creating a PDF using an XML output to produce a publication that
has a drug list and an index page that references every drug by page
number on the drug list.
I have the drug list created and can produce the PDF however the Index
page has me stumped.

The XMLS Schema looks something like this:
<Root>
<MEDDDRUG>
<MEDDDRUGN>This text shows up on the Drug List</MEDDDRUGN>
<MEDDTIER></MEDDTIER>
<MEDDBD> </MEDDBD>
<MEDDPA></MEDDPA>
<MEDDQL></MEDDQL>
<MEDDST></MEDDST>
<MEDDINDEX>This text shows up on the Index Page</MEDDINDEX>
</MEDDRUG>
</Root>

The Drug lists is pretty simple. All it does is list out all drug names
in the <MEDDDRUGN> tag in a column format. The Index page should list
out all drug names found in the <MEDDINDEX> tag and reference pages that
the drug name shows up on the drug list. For Example, Lets say
Allopurinal shows up on the drug list 3 times(on pages 2,4,10). Then the
index should look something like:

*A*
Allopurinal
.............................................................. 2,4,10
Other A drugs .........................................................
#,#,,,

*B*
Other B
drugs..........................................................#,#,,
.
.
*Z*
Other Z
drugs...........................................................#,#,,

I have searched online for a good example but could not find any that
fit well. If any one has some ideas please let me know. I do have the
working XSL and XML that currently build out the drug list if needed.
Thanks in advance for any one with the knowledge to solve this problem.