Useing (='sheet'!cell) if the sheet name is depending on cell

Hello,

how to use (='sheetname'!targetcell) if the sheetname is in cell A2(sheet1) and the target is C3

='sheet1'!C3 is working, but the sheet name is depending on A2

i got an error if i type (='A2'!C3) is there another way for it?

thank you