Mixed Classes/Cross-class Groupings

My predicament may be unique as a music teacher. I have two classes of first grades, but I don't see them by homeroom. They are in "temporary" reading groups until the end of the month. Then they will be in semi-permanent reading groups until February - when they will be reevaluated and possible reassigned. However, when filling out reports, the reports are grouped by homeroom.

Is it posible to have the two homerooms as classes (1R and 1F) AND assign them to one of two other groups as well (blue group, white group)...AND have the data that I enter into the color groups automatically be copied into the homeroom classes?

My apologies if any of that is confusing. Heaven knows that it confuses me sometimes.

Hi MissV,
Certanly a unique predicament!
I've got one question though (sorry if I missed that part), when you see students in their temporary reading group, do they belong to a unique subgroup of class 1R for example? or is it a subgroup that may contain students from both 1R and 1F?
If you don't mind clarifying that part, I'll see if I can think of some elegant solution tomorrow