How to output from lookup table if a field value is included anywhere within table field

[epw0rrell]

I know how to use eval and if statements to pull fields that contain a %.value.% but how can I use this when running a search | lookup and output fields that contain a value of a field within the search?  Let me know if you need an example search or more context.  Thanks to anyone that can help me with this.

[ITWhisperer]

An example and more context would be helpful

[epw0rrell]

I have one index of alerts containing a field named "alertDomain" with values like "domain.com."

I have a lookup table with urls sent within emails with values like http://www.domain.com/otherplaces 

I would like to run a search like this:

index=alerts | lookup emailURLs.csv emailURL as alertDomain OUTPUT emailURL as phishingURL | table phishingURL

but I know this won't work because the fields will not match.  I need to OUTPUT the emailURL if it simply contains the value within alertDomain.

Is this a bit better?

[ITWhisperer]

Can you add another column to the emailURLs.csv file with the domain part of the URL so that you can get a match?

[epw0rrell]

Unfortunately there is only a URL field within the logs.  Unless I can use a clever field extraction on the URL, I would need to go about it from this direction.