passing an RPG variable length field to a CL as fixed length

I have an RPG app calling a CL app. The RPG app as a variable length field for a message that I need to cut down to a fixed length 160 byte field to pass to a CL program. If I look at the variable TEXTMsg160 just before the call I do not see the length part of the variable field but when the CL program gets &MESSAGE and I use a SNDMSG to see what it contains there are who hex characters in the front. I can only guess that this is the length of the variable. Shouldn't the EVAL that moves the string from the variable length field to the fixed length field also remove the length part of the variable length field? If not how else can this be done?

The RPG fields are defined as...
D TEXTMsg S 5000 VARYING
D TEXTMsg160 S 160

The code is ...
C EVAL TEXTMsg160 = '(PCTAlerts) ' +
C %trim(TEXTMsg)
C CALL 'UTJSMSMSG' SndSmsMsg

The CL is defined as...
PGM PARM(&PHONE &MESSAGE)
DCL VAR(&PHONE) TYPE(*CHAR) LEN(10)
DCL VAR(&MESSAGE) TYPE(*CHAR) LEN(160)