=SUBSTITUTE(C2,"¥","")
https://officepress.net/googledocs/function-spread/value-spread.html
VALUE|文字列を数値に変換する
2018/04/02
=IF(REGEXMATCH(E2,"−"),-VALUE(SUBSTITUTE(E2,"−","")),VALUE(E2))
https://www.officeisyours.com/entry/2020/12/06/124515
2020-12-06
(Gスプレッドシート)指定した文字列を含むか判定する