そんなのは

as for such a thing

→ そんな
phrase Rare #24,727
as for such a thing A casual way to refer to something like that or that kind of thing as the topic of a sentence. そんなの is often translated as “such a thing” or “that kind of thing,” and は marks it as the topic.
JA: そんなのは気にしなくていいよ。
EN: You don't need to worry about that kind of thing.

そんなのはとても無理だった

That was simply impossible for me.

— スター・トレックII カーンの逆襲 (1982)

そんなのは助けじゃない

That's no help.

— ソング・オブ・ザ・シー 海のうた (2014)

そんなのは知らん

I don't know anything about that.

— エリート・スクワッド (2007)

そんなのはいらん

I don't need that.

— ドライヴ (2011)

そんなのは許されません

That's unacceptable.

— ラスト、コーション (2007)

そんなのは不公平だろ

That's not fair, is it?

— ザ・マン・フロム・アース (2007)

そんなのはありえない

That's impossible.

そんなのは言い訳に過ぎない

That's nothing more than an excuse.