macro to copy specific cells from multiple sheets

Hello all,

I need a macro to copy certain cells from many sheets into a new one. I am attaching a sample. what I want to do is copy cells "G5" "G6" "G18" from the sheets with the month names (not the main one) into a new one and put them in three different columns (all G5s, G6s, G18s).

Many thanks in advance