Is there a way to define a subtree as a type in snmp?

I would like to create an ASN1 definition of a tree, as a type. So I can assign this type to more than one node. If I could do that, I could create multiple, complex tree-shaped definitions (including tables), while only having to define them once. I need this, because I have a set number of complex-functions performing network interfaces, and I imagine it to look something like this (pseudo ASN1):

-- This is where I'm going to hang multiple trees under, defined once
fooInterfaces ::= oid { enterprises.foo 1 }

-- Type definition of the tree; I don't know how this step works
MyTreeType ::= oid

-- The contents of the tree (partly)

mtu ::= Unsigned32 { MyTreeType 1 }

macAddress ::= OCTET STRING { MyTreeType 2 }

ipaddressTable ::= sequence of etc. { MyTreeType 3 }

arpTable ::= sequence of etc. { MyTreeType 4 }

-- Hanging the above trees under the endpoint

interface1 ::= MyTreeType { fooInterfaces 1 }

interface2 ::= MyTreeType { fooInterfaces 2 }

Addressing the mtu for interface1 would then be as simple as enterprises.foo.1.1.1.0; MAC address for interface2 would be enterprises.foo.1.2.2.0, etc.

I don't see any way that ASN1 now allows for this kind of definition, but I'm a relative noob, so if you have some advice (other than 'you shouldn't want to do that') I'd really appreciate it.

KJ