# best subset of moderators for meta-analysis in R

I have a large number of "categorical" moderators (35 moderators). I am planning to use the best subset of these moderators that can maximally explain the variation in my 257 correlated effect sizes from 51 studies.

The R package leaps does perform best subset analysis for [weighted] OLS regression via function regsubsets() but to make that suited to meta-analysis (e.g., using robu() from package robumeta) I think need to define weights argument in regsubsets() so I can basically make this suited for RVE (Robust Variance Estimation) purposes not simply OLS regression.

Any idea regarding how I can execute my plan in R or generally how I can choose best subset of moderators for robu() in robumeta in R?