"partition magic"

Hi Experts,

I have a DOS-partition and a Linux-partition.
Is there a way to take some space from my DOS partition and to add that space to
my Linux partition ?
In short : I want to make my Linux partition bigger and not create two separate Linux
partitions.
I know FIPS : but that's only splitting a partition in two.
I know Partition Magic : but that work's only with DOS partitions...
Or is there a tool to add two partitions (with some data on it, using the same Linux FAT-
structure)
to make one ?

Thanks in advance,