multi table import from 1 denormalized source table

Hi,

I frequently get tables from spreadsheets to import into the DB.

Usually it looks like this:
A1, A2, A3, A4, B1, B2, B3, with optional C1, C2, D1, D2, ...

and there is a 1:n relation between A and B.
If provieded the C would be 1:1 to A and D 1:1 to B.

Up until now I let a VBA script order the source table by A, then scan
the table line by line and create a new entry in the target table A* and
fetch its serial ID everytime the script figures that A changed.
With this IDa create 1 C* and as many B*s until A changes again ... and
of course fetch IDb to attach the D* records with a foreign key column.

Now I'm trying to get away w/o the VBA stuff.

Is there a clever way to split such denormalized sources while still
obtaining the needed IDs to connect everything?