How to include header from an event for splunk to recognize as the first line of the event log

[Mo7860]

I have a sample log, how do I create line breaking in props.conf on the indexers so that splunk can recognize the header (###) as the first line of the event message

sample log

########################################################################
Thu 05/02/2024 - 8:06:13.34
########################################################################
Parm-1 is XYZ
Parm-2 is w4567
Parm-3 is 3421
Parm-4 is mclfmkf
Properties file is jakjfdakohj
Parm-6 is %Source_File%
Parm-7 is binary
Parm-8 is
Parm-9 is
SOURCE_DIR is mfkljfdalkj
SOURCE_FILE is klnsaclkncalkn
FINAL_DIR is /mail/lslk/jdslkjd/
FINAL_FILE is lkjdflkj_*.txt
MFRAME is N

Version
(C) Copyright
*************************************************
Successfully connected

I want splunk to include the ### as the first line of the event message, but I am able to get line breaker from the second line Thu 05/02/2024 - 8:06:13.34

Please let me know

[marnall]

You should set the LINE_BREAKER field in your props.conf in your indexer machine(s). You can also set SHOULD_LINEMERGE = false to prevent Splunk from recombining the events.

[yoursourcetype]
LINE_BREAKER = ^()\#{72}\n[^\#]*\#{72}
SHOULD_LINEMERGE = false

Since your log header includes two lines of hashes, the REGEX should find both of them.