To expand slightly on Trond's (absolutely correct) answer...
There is no 'process', really, that you have to employ in order to place a block on a line a certain way. As Trond said, ACADE will do what it can do make that happen.
Specifically, when you are creating symbols for this software, you need to create two versions: one, dedicated for horizontal placement, the other for vertical. The naming conventions show you how to name them so that ACADE can handle them properly. So, a horizontal relay coil symbol would be named HCR1 and its vertical counterpart would be VCR1.
Where I work, we make OEM task-specific machinery mostly for the bourbon industry. Our equipment never leaves the USA. We loosely follow the NFPA standard. Our drawings rarely leave the company, excepting the set we include with the purchase of the machine. Because of this, I never have to draw to the European standard. My drawings are practically 100% 'horizontal' as far as symbol placement goes.
So, when I need a custom symbol, I only draw one version, the horizontal one. On the rare occasions when I need a symbol to be vertical, I just let ACADE use the horizontal version and I deal with re-positioning the weirdly-placed attributes. For me, it's faster to do this, than it is to draw two versions of every custom symbol.
Just FYI, in case that saves you time. Hope this helps,
Jim

Jim Seefeldt
Electrical Engineering Technician