Hi Ygsla,
Yes we could do PK modeling using Phoenix NLME or with RsNLME (R Speaks NLME). I have attached a youtube link which takes throught the process of simulation using Phoenix. Please let us know if you need furhter assistance.
Also, if you are new to Modeling I would recommend you to consider our online course at Certara University or PML School at Certara Forum.
Thanks
Mouli