Problem with route determination

Hi!

I know how route determination work i've studied very long time and basicly i know how works. Now i have requirenment that all materials in sales order which will be shipped from certain shipping point must have certain route. OK i do some work to assign on shipping point different deparure zone and mantain this route in determination. problem is that standard route determination takes shipping point and subsequently departure zone from table TVSTZ (assign shipping points) and field proper shipping points. problem is that i have on plant many shipping points and one it must take is from manual shpipping point. so no matter what i do system doesnt take proper shipping point and also departure zone.

and also i have UE MOVE_FIELD_TO_VBAP to assign on SO shipping point that i want. so in table VBAP it is proper shipping point but for route determination it doesnt take from VBAP but TVSTZ

UE to proper assign shp. pt. 750H ( transportation zone assigned to 750H is NL00000002)

route determination is proper ( for shipping point and ship-to party)

yet route determination departure zone take from shp. pt. 7500 which is NL00000001

and than takes route which is different that i want

how can I overcome this problem. is any standard resolution for this?