Error Propagation of Variable raised to Variable

I am an environmental scientist and it’s been too long since I’ve taken a math class. In my research I’ve had to use this equation for gas loss constants, but I am going back to assess my uncertainties. I did all the easy uncertainties in my calculations, but this formula has me stumped. I am not sure how to apply error propagation to a variable raised to a variable. It comes up in this equation:

$$k= 0.45W^{1.6left(frac S{600}right)^{-0.5}},$$

(I gave actual numbers from one row of my data for ease of use) where W is $5.376 pm 17.383$ and S is $796.825pm 258.418$

K is a gas loss constant, S is the Schmidt number and W is the wind velocity in m/s.

I have run into the formulas (simplified ones) for a variable raised to a power as in:
for $a^n=Q$, where $text{d}a$ and $text{d}Q$ represent the error of $a$ and the error of $Q$,

$$dQ= |Q||n|bigg(frac{text{d}a}{a}bigg)$$

and for a constant raised to a variable as in:
for $e^a=Q$, where e is a constant, a is a variable with an known error (d$a$) and $Q$ is the resultant number with its own resultant error (d$Q$),

$$dQ=sqrt{Q^2(text{d}a^2)}$$

I don’t think either of those apply in my case as the base nor the exponent are constants. It has been way to long since I took Calculus and I need some help.

Please if I have my formula’s for error propagation wrong let me know and more importantly if you know how to propagate these errors please show me how.

Thank you anyone who takes the time to read this.