I need to write a formula to do the following and it's just feeling way over
my head. I know I need an "if" at the beginning but then I get lost. Can
anyone help?

Col A Col B Col C Col D
Date $Amt Type Text Code

If the type in row 1 = X, find the minimum $Amt from all the rows where
Type=Y or Z, AND Date is within 30 days of the Date in row 1.