Just create all tablespaces manually before you start the import.
Then you will get the error "cannot create tablespace .." - but it will create the tables and import the data.

I assume that you don't have too many tablespaces and you know them.

Otherwise you can try following:

imp username/pw file=youfile.dmp indexfile=create_commands.txt


==> this will create an ASCII-file containing all "create table" and "create index" (and I hope also "create tablespace") commands, but no data.

Good Luck,