How would I write an IF statement where my logical test is looking for
a range. i.e A1=91
Is it possible to write an if statement where I am looking for the
range in A1 to be a range between 90 and 100. I don't seem to be able
to find anything in microsoft help that allows you to return a value
if true on a range.

One way:
=IF(AND(A190,A1<100),"in range","out of range")