You could do the if{...}elsif{...}elsif{...}else{...} things, but much simpler would be to set yourself up some hashes that will convert the strings to their bitmap constant values like this:

#! perl -sw
use strict;
use Win32::Perms;
my %ACE_masks = (
    FULL        => FULL,        # Full access (RWDXOP)
    ALL        => ALL,            # Same as FULL
    CHANGE    => CHANGE,        # Change access (RWDX)
    READ        => READ,        # Read access
    WRITE        => WRITE,        # Write access
    DELETE    => DELETE,        # Delete access
    EXECUTE    => EXECUTE,        # Execute access
    NO_ACCESS    => NO_ACCESS,    # No permissions specified
);

my %ACE_types = (
    ALLOW        => ALLOW,        # The permission mask is allowed
    GRANT        => GRANT,        # Same as ALLOW
    DENY        => DENY,        # Permission mask is denied
    AUDIT        => AUDIT,        # The permission mask is for auditin
+g
    OWNER        => OWNER,        # The account specified is the OWNER
+ (the permission mask is ignored)
    GROUP        => GROUP,        # The account specified is the GROUP
+ (the permission mask is ignored)
);

my %ACE_flags = (
    DIRECTORY    => DIRECTORY,    # The permission is for a directory
    DIR        => DIR,            # Same as DIRECTORY
    KEY        => KEY,            # the permission is for a Registry k
+ey
    CONTAINER    => CONTAINER,    # The permission is for a container 
+object (dir, Registry key, etc)
    FILE        => FILE,        # The permission is for a file
    NON_CONTAINER    => NON_CONTAINER,        # The permission is for 
+a non container object (file, etc)
    SUCCESS    => SUCCESS,        # If the type is AUDIT then this wil
+l log a successful audit
    FAILURE    => FAILURE,        # If the type is AUDIT then this wil
+l log a failed audit
);
[download]

This is only a subset of those exported by Win32::Perms, but it may be enough for your needs.

You would use these in a snippet from your code like this:

...
$perms->Add('MYDOMAIN\bloggJo', $ACE_masks{$ARGV[1]}|$ACE_masks{$ARGV[
+2]}
    ACCESS_ALLOWED_ACE_TYPE, OBJECT_INHERIT_ACE | CONTAINER_INHERIT_AC
+E);
[download]

This will take the 2nd string that you supply on the command line as $ARGV[1] (ie. READ), use that as the key in the %ACE_masks hash and retreive the corresponding bit map. The same for the 3rd command line parm $ARGV[2] (WRITE) and do the same. It will then binary or (|) these together and then supply the result to Add().

If you need to supply a variable number of arguements, then you will need to loop over the @ARGV array, lookup the strings, oring the values into a scalar and then pass those.

If you get stuck with that, come back.