PROCESS plugin question (controlling for variables)

I have a question regarding the PROCESS plugin for SPSS developed by Andrew F. Hayes.
The analysis I'm running has one predictor, one outcome variable and 6 mediators (there are no interactions).
For this analysis I want to control for 3 dummy variables that could have an influence on the outcome variable.
Is there any way to plug these into the PROCESS analysis?
I am able to control for them using an MRA where I add these dummy variables as predictors but in the PROCESS
plugin it only seems possible to add covariates and just one predictor variable.
Is there any way to control for them or should I just use the MRA results to explain the difference in
explained variance with and without controlling for these variables?
Also when running an analysis with multiple mediators I do not get a kappa squared (k2) value in the output,
is there any way to get this?
Any help would be greatly appreciated.