What is wrong with my Formula?

Hi, under the write line activities I have this formula:

String.Format("=IF(LEFT({0},15)={1},UNICHAR(10004),UNICHAR(10007))", CurrentRow.ByField(“Class ID”).ToLower, CRandNotes.Sheet(“Closure”).Cell(“A1”).ToLower)

I received an error stating that the format might be wrong? Can any one spot it?

In WriteLine it will not accept excel formula

@Divyanshu_Divyanshu Sorry, what do you mean? I wrote the stringformat as an excel formula.

“=IF(LEFT({0},15)={1},UNICHAR(10004),UNICHAR(10007)”
this an excel formula which vb.net or c# not support if i am not wrong