Clean Command doesn't work in WinXP

Have installed Aspell-0-50-3-3.

I  have a wordlist with nonalphabetic characters that need to be
removed. Supposedly, this can be done using Aspell's "clean", or
"clean strict" command.

Using this command at the WinXP command prompt :

         aspell --lang=en_US clean strict < NewDict.txt > result.txt

In this directory:

         C:\program files\aspell\bin\

results in this message:

         Error: Unknown Action: clean


Is there something wrong with the command; does it need to be modified
for WinXP, does the Aspell clean command just not work in WinXP; will
installing v0.60.6.1 make a difference?

Thanks for your help.