apache .htaccess to OLS migration

I have the following htaccess and need to migrate to OLS, unfortunately I am not successful with the rewrite rules.

The main setting should work as described here:
www.domain.com/filename.de.htm should be handled by the parser www.domain.com/phpcms/parser/parser.php?file=/filename.de.htm

My Questions
1. Do I need RewriteEngine On in OLS?
2. Do I have to set the type as Apache handler in the apache configuration? AddType application/x-httpd-parse .htm
3. Do you have any hint for the RewriteRules? I tried the 3 separately, and some more, but not successful. Other posts discussed the ^/ entry point options

RewriteEngine On
AddType application/x-httpd-parse .htm
Action application/x-httpd-parse "/phpcms/parser/parser.php?file="

RewriteEngine On
RewriteRule ^/(.*)$ /phpcms/parser/parser.php?file=/$1[L,R=301]
RewriteRule /(.*)$ /phpcms/parser/parser.php?file=/$1[L,R=301]
RewriteRule (.*)$ /phpcms/parser/parser.php?file=/$1[L,R=301]

thx a lot for any hint