Can I fuse rows together into one unit? (Not merging.)

I have a spreadsheet that is conditionally formatted to alternate color at
every 5th row.

The five rows are merged into one cell at the first column; the rows are not
merged for the other columns. (For example, one contract number applies to
all five rows--so, the merged cells in the first column, along with the
shading, show that the five rows belong to the same contract.)

When I use the autofilter feature--my grouping totally disappears. The
filter erases every row within the group that doesn't have the filtered info.

Is there a way to "fuse" the group of rows so that they act as one unit?
I'd like for all five rows to show up when one of the five rows WITHIN THE
GROUP has the information in the filter. It would also allow me to sort the
first column by number without losing the adjacent rows that are part of that
group.

Thanks in advance!