Have you read the tutorial linked in my signature? There are two bits of sample code which would help, the first in defining character ranges and the second if replacing file extensions. To make a long story short, all you need is:
# .htaccess in DocumentRoot
# Replace extension for directory/filename in artman2/publish directory
# Note: Apache 2.x assumed
RewriteRule ^artman2/publish/([-a-zA-Z]+)/([-a-zA-Z]+)\\.asp$ artman2/publish/$1/$2.php [R=301,L]
What you were missing was the leading - and uppercase characters in the character range definitions (and a redirection in your RewriteRule).
You might benefit from reading the mod_rewrite tutorial linked in my signature as it contains explanations and sample code. It's helped may members and should help you, too.