Multiple imputation with longitudinal data

Have been working with Sarah on revising our comparative paper. One problem we need to solve in this revision is the presence of large amount of missing values. I use "ICE", a user contributed module in Stata to do the imputation. Unfortunately, the built-in estimation procedures does not include "XTMIXED" or "GLLAMM". I have to import the imputed data sets into Mplus and do the estimation there.