LONGCHAR, CHAR, and CLOB

A little while ago I posted this question: https://community.progress.com/community_groups/openedge_development/f/19/p/34051/105431#105431

and that worked fine, but now I'm having another problem.

It's common for me to make a helper procedure to facilitate adding lines to the log.

Obviously this procedure takes an INPUT PARAMETER that represents the line to be added.

It normally looks like this:

PROCEDURE LogCCMsg :

DEF INPUT PARAM ip-msg AS CHAR NO-UNDO.

IF NOT AVAIL tt-pay THEN
  MESSAGE "[LogCCMsg]" SKIP
          ip-msg
          VIEW-AS ALERT-BOX.
ELSE
  tt-pay.proc_log = tt-pay.proc_log + ip-msg + CHR(10).


END PROCEDURE.

When I'm just dealing with CHAR fields, this is just fine, but tt-pay.proc_log is a CLOB field as suggested in the earlier question, so I get this error:

** Incompatible data types in expression or assignment. (223)
**  Could not understand line 3341. (196)

I've tried varying the type of the parameter, but it doesn't like anything I try.

also, the code that calls this just looks like this: RUN LogCCMsg("--DECLINED--"). Nothing fancy there.

Any Help would be appreciated!

-Ken