For each entry (hidden off to the side of your main logbook screen area)
=if(D4="C172",sum(H4:L4),"")
D4 is reference cell for aircraft type
sum(H4:L4) is the range of columns you want to be added for the flight if the answer is true i.e. C172
"" means blank/zero will be the answer if the answer is false.
Create as many columns with the formula above that you have type ratings.
Highlight all your different rating formulas and drag down to your last avail row to repeat the formulas for each flight entry.
Have a total at the bottom of each column.
Back on your main logbook screen area, under your totals rows for your PIC/DUAL/MULTI etc have a section for your different types, with the time on type next to each by using the simple formula =Y325. where Y325 is the total of column that you created for your C172 rating.
*All cell references are for example purposes only.
Just had a look at Das Uber's spreadsheet, very techy and beyond my excel capability. My info above is a more longwinded, layman affair if you will.
Cheers
S2K