Greetings Brian ...
you're thinking of the quick and dirty demo that I made for a couple of the students who were interested in using Excel for data collection ...
here are the basic steps ...
go to RSLinx and click the DDE/OPC menu selection ... (note that if the word "Lite" appears in your RSLinx title bar, then this will NOT work ... in other words, the "free" version of RSLinx will NOT make this type of connection) ...
highlight the processor that you want to connect to ...
click on the "New" selection button to create a new topic ...
give the new topic a name (example: BRIAN) ...
click the "Done" button ...
now go to any cell in Excel and type the following:
=RSLINX|BRIAN!'MY_TAG'
where the | character (called a "pipe") is usually the shifted Backslash key on your computer ...
notice the ! (exclamation point) right after the topic name ...
and MY_TAG is the name of the data tag in the processor ... (this is just an example ... substitute whatever tagname you need) ...
put Single-Quotes (apostrophes) around the tagname as shown ... Excel might drop those if it doesn't need them – but put them there just in case they're needed ...
proper syntax and punctuation are CRITICAL ...
DISCLAIMER: I'm writing this from memory ... if you have problems, post a screen shot of what you've got and we'll try to correct it ...