Alternative to Filter in older excel?

Hi all, my wife asked me to help her solve a problem she was having manually pulling out keywords from email subjects and displaying them in another column. This uses a list of keywords and is performed on a list of subject lines.

We eventually landed on using TextJoin/Filter/IsNumber/Search which worked really well - until I copy-pasted my formula to her and we realised she's using an older version where Filter doesn't work.

I *THINK* I've attached a copy of a spreadsheet showing how I'm using the formula, obviously simplified to remove confidential info.

Any suggestions for a simple solution that works without Filter greatly appreciated.

ps; she will have many more keywords and subject lines than my example and they may vary over time.

One possibility (of many!!):

=IFERROR(LOOKUP(1E+100,FIND($A$2:$A$5,C2),$A$2:$A$5),"")