How to derive confidence intervals and SD for contrasts in linear mixed effects models?

Hi,

I am looking for a way to derive confidence intervals and SD for arbitrary contrasts in a fitted linear mixed effects model (fitted using Matlab's fitlme function). More specifically, the coefTest function allows - using the matrix H - to compute statistical tests between any combinations of fixed effects. I would like to have along with these statistical values confidence intervals and SD. However the function coefCI that seems to be the corresponding function, has no option to provide a contrast matrix H. As I understand, coefCI only provides confidence intervals for each single fixed effect but not for combinations.

I would be grateful for a solution.

Thank you,

Jörg