Simpler method:
Subtract your TAS from you GS for tail or head component. TAS equals your IAS plus 2% per thousand feet of altitude. Ex.: 300 IAS at F200 equals 300 + (40% of 300) equals 420 knots TAS
Multiply your crab angle by your TAS in nm per minute equals your crosswind component. Ex.: 420 knots equals 7 nm per minute, so a 6* crab equals 42 knots of crosswind.
Then, scale them out on the HSI.
Ex.: 100 knots of tail and 42 knots of right cross, starting with the airplane symbol, the outer edge is 100, the middle of the right side is about half way (50 knots), so a little inside that is 42 knots. Then connect the two points with a pencil slide the pencil or the line over the airplane symbol. The length of the line compared to the distance of 100 is the speed of the wind; the heading is read on the HSI.
Not perfectly accurate, but close and good sanity check. Too much time in old fashioned planes and not a math major, besides the FMS figures it all out anyway. Are you really going to use a spreadsheet in a plane?