BW Connection to SAP R/3 4.6C

Hi,

i need to connect a BW 7.4 to a R/3 system 4.6C.

but in the 4.6C we have

But we don't have PI Basis plugin, so we don't have any BW transaction in R/3

My question is :

Can i install the basis plugin and then connect R/3 to BW ?

Where can i found source for basis plugin ? which version do i have to install ?

is there another way to connect R/3 without installing the basis plugin ?

Thanks for help.

Regards

Cyril