Interlinings for connecting flight

Heyho! :)

I'm currently working on an airline system in Nepal.

There's a regional subsidiary and an international subsidary. The international airline has an interlining at some given airport. Will passengers from the regional airline be able to connect to airlines that the international airlines has interlinings with?

Following example:

Let's say "Nepal Internatonal" has interlinings with "China 123" at Beijing, Nepal Regional doesn't

Nepal regional: Lukla- Kathmandu

Nepal international: Kathamdu- Beijing

China 123: Beijing- Harbin

Will passengers be able to book the ticket from Lukla to Harbin, even though Nepal Regional doesn't have an interlining agreement with China 123?

Thanks in advance :)

As far as I know yes in case IL's are signed as follows:

Nepal regional <> Nepal international and Nepal international <> China 123

What Rainer says is 100% correct

Thanks a lot for the quick response guys! :)