I found a similar method which works
statusItem = [[[NSStatusBar systemStatusBar] statusItemWithLength:NSVariableStatusItemLength] retain];
NSFont *font = [NSFont fontWithName:@"LucidaGrande" size:12.0];
NSDictionary *attrsDictionary = [NSDictionary dictionaryWithObject:font forKey:NSFontAttributeName];
NSAttributedString *attrString = [[NSAttributedString alloc] initWithString:@"title" attributes:attrsDictionary];
[statusItem setHighlightMode:YES];
[statusItem setAttributedTitle:attrString];
[statusItem setMenu:statusMenu];
thanks