Example
Mytitle > itle
Mytitle > Myti
Cheers
Mohammad
[[Mytitle]split[]rest[3]join[]]\define remtitle(MyTitle:"")<$text text={{{ [<__MyTitle__>split[]rest[3]join[]] }}} />\end
<<remtitle mohammad>><<remtitle ali43>>ammad
43
Regards,
Mal
Just keep in mind that split and join are new operators being introduced in 5.1.20 and I don't know if their behaviour is fully locked in yet.
Mal