I think the function you are after is MaxVal, not maxv.

Also, if you want to define A11 using type vars, you need to include the series definition.

vars A11 = series(MaxVal(Data, TimePeriod));

However, I'm not sure if you can use this to achieve what you want (which as I understand it is the highest high from 36 bars ago to 32 bars ago??). For this, you might need to use a series of nested if...else if statements using the function 'max' which I believe can only support two arguments at a time (hence the need for nested if...else if's).