cast sequence macro with different targets?

[Shogun]

is it possible to a castsequence macro which has a different target

Sadly, no.

Just so that the question gets answered directly.

you don't need to:

/targetparty
/cast Mark of the Wild (or however you spell it)

From Wowwiki:

/targetparty, /targetraid

Cycles through your nearest party or raid members. Like /targetenemy, you can add a 1 to reverse the direction.

Just click that once to buff each character, will target themselves as well, so 5 clicks should do it