Regular expression not valid on i

[MWHopkins@xxxxxxxxxxxxxxx]

I am trying to use a regular expression that I validated in a pc program 
(The Regex Coach) but is throwing an error when I try to us it on my 
system. When the regcomp() process runs on the i5 I get the message: "?, * 
or + not preceded by valid regular expression." The Regex Coach says it is 
valid and is finding the strings I want it to.

The regex I am trying to use is:

^.*?CREDI(T ?)?L(I|Y)(NX|NK|NKS)((?!CAN|\bca\b).)*$

I think the i5 is not liking the last group ((?!CAN... because when I 
remove it I don't get the error.

Ultimately this is what I want:
CREDITLINX ANYTHING     <= VALID
CREDITLINX CA ANYTHING  <= NOT VALID

Is there a reference somewhere that I can find out what expressions are 
valid on my system?

I'm on v5r4.

       cflags = REG_EXTENDED + REG_ICASE + REG_NOSUB;
       rc=regcomp(preg:RegexString:cflags);

Matt Hopkins 
Sr. Programmer/Analyst 
Web: www.pdpgroupinc.com 
Email: MWHopkins@xxxxxxxxxxxxxxx 
Office: 410-584-0330 
Fax: 410-584-0336 
Cell: 410-258-8845 


The information contained in this communication may be confidential, is intended only for the use of the recipient named above, and may be legally privileged.  If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication, or any of its contents, is strictly prohibited. If you have received this communication in error, please re-send this communication to the sender and delete the original message and any copy of it from your computer system.  Thank you.