Match interface starting with.

I want to script adding interfaces to an vrf. Each time I want to add an interface to a vrf I have to repeat every interface already in there.

For example:
If vrf is:

 1   routing-mark=Customers interfaces=ether1,pppoe-cust3

And wan’t to add interfaces pppoe-cust1 and interface pppoe-cust2, I have to set

ip route vrf set interfaces=ether1,pppoe-cust3,pppoe-cust1,pppoe-cust2 1

Instead of repeating each interface already set for vrf, Can i do someting like?:

ip route vrf set interfaces=ether1,pppoe-* 1

So matching each interface starting with value "pppoe- "
How can this be accomplished in routeros scripting?