I found this solution which I'm pretty sure will do exactly what I'm trying to accomplish, unfortunately, all my SQL is self-taught and I can't figure out how to integrate the solution into the query I'm working with.
I tried putting everything above the SELECT statement, but I couldn't set the @testString variable to the COND_NOTE.TEXT field, which makes sense, since all of that happens inside the main query select.
Apologies for essentially asking someone to give me a crash course in presumably a pretty basic application of SQL syntax.
SELECT
CASE WHEN DM_IAM_D_I_ROOT.ZZCAP_FACILITY = 'N200' THEN 'MT'
WHEN DM_IAM_D_I_ROOT.ZZCAP_FACILITY = 'N202' THEN 'PI'
WHEN DM_IAM_D_I_ROOT.ZZCAP_FACILITY = 'N204' THEN 'FL'
ELSE 'Err' END AS FAC
,right(DM_IAM_D_I_ROOT.ISSUE_ID,12) AS ISS_ID
--The following line is the one that I want to use the solution from the referenced question in.
,REPLACE(REPLACE(COND_NOTE.TEXT, '"', '"'), 'br/>', '') NOTES
,COND_NOTE.LINE_COUNTER
FROM
DM_IAM_D_I_ROOT
LEFT JOIN
(
SELECT
DM_BOBF_D_TXCROOT.HOST_KEY
,DM_BOBF_D_TXCROOT.MANDT
,DM_BOBF_D_TXCTXT.TEXT_TYPE
,DM_BOBF_D_TXCCON.LINE_COUNTER
,DM_BOBF_D_TXCCON.TEXT
FROM
DM_BOBF_D_TXCROOT
INNER JOIN DM_BOBF_D_TXCTXT
ON DM_BOBF_D_TXCROOT.DB_KEY = DM_BOBF_D_TXCTXT.PARENT_KEY AND DM_BOBF_D_TXCROOT.MANDT = DM_BOBF_D_TXCTXT.MANDT
INNER JOIN DM_BOBF_D_TXCCON
ON DM_BOBF_D_TXCTXT.DB_KEY = DM_BOBF_D_TXCCON.PARENT_KEY AND DM_BOBF_D_TXCTXT.MANDT = DM_BOBF_D_TXCCON.MANDT
WHERE
DM_BOBF_D_TXCROOT.MANDT = '100'
AND DM_BOBF_D_TXCTXT.TEXT_TYPE = 'ZCOND'
) COND_NOTE ON DM_IAM_D_I_ROOT.DB_KEY = COND_NOTE.HOST_KEY AND DM_IAM_D_I_ROOT.MANDT = COND_NOTE.MANDT
WHERE
DM_IAM_D_I_ROOT.ISSUE_TYPE = 'CAP'
AND DM_IAM_D_I_ROOT.MANDT = '100'
AND DM_IAM_D_I_ROOT.LCYCLE_CD NOT IN ('10', '64')
ORDER BY ZZCAP_FACILITY, ISSUE_ID, LINE_COUNTER