r - Plot explicit cdf over ecdf

Question

I have some data and I just plotted the empirical cumulative distribution using Ecdf like this:

Ecdf(data)

Now, I tried to adjust the parameters (lambda, mu, sigma) for a mixture of two normals to this data, and now I would like to plot the cdf of this model using and explicit function over the plot created by Ecdf, is there any way to do this or I just have to simulate data so then I can use again Ecdf?

The explicit function, just to illustrate is something like:

ipc_values_EM$lambda[1] * dnorm(x, ipc_values_EM$mu[1], ipc_values_EM$sigma[1]) 
+
ipc_values_EM$lambda[2] * dnorm(x, ipc_values_EM$mu[2], ipc_values_EM$sigma[2]) 

(as you can note, is the mixture of two normals different mu's and different sigmas)