Google Sheets IF Function using "one of many" values

I'm trying to figure out a faster way to write this function:

IF(X1=A1;B1:H1;IF(X1=A2;B2:H2;IF(X1=A3;B3:H3; //and so on up to If(X1=A400;B400:H400))))

What I want is basically, if X1 equals any value from the range A1:A400, then I want the corresponding row inserted. For example, if X1=A50 I want the range B50:H50 inserted, If X1=A199 I want the range B199:H199 inserted and so on. Is there a way to achieve this without writing over 400 lines per hand?