replacing text found using reglar expression

To all,

            I use regular expressions to find text a lot.  Now I need to
replace text (or in the current case append new text). My example is 

 

Before:

     A            CDPHMCP   R               REFFLD(POSFLAG)  <-- there a
a lot more of these lines

After: 

     A            CDPHMCP   R               REFFLD(POSFLAG) ALWNULL

 

I use Find, using regular expressions like: reffld\([A-Z]*\)$  The
reference name will not always be the same and in many cases is not, so
the replacement text cannot be static.  

 

Does anyone know of a way in WDSC find/replace tool to replace using a
regular expression pattern?  Something like...

 

FIND:   REFFLD\([A-Z]*\)$  

REPLACE:     REFFLD\([A-Z]*\)$ ALWNULL

 

(Case sensitive = off)

Thanks, Matt