Did you buy the dipstick from your dealer? How much was it? Did you know that the temperature must be quite precise to measure the fluid level? If not, you will under/over fill it, and damage the transmission. The dealer uses a computer to determine when the fluid temp is precisely 80C for level setting.
Good luck. I paid the $60 in labour and had the dealer do it. Cheap compared tot he potential for damaging the 722.6 tranny...
1998 C230 "Black Betty"