Welcome to the forum, @donali.
If you had a 'lot' to do, I would buy a cheap dowelling jig such as this,
www.timbecon.com.au
I have had some success with these simple jigs.
I believe Wolfcraft sell one similar in Europe?
I may not have grasped what you actually intend to do, so a quick diagram would help. Draw it and take a picture with your phone to post on the forum.
If you had a 'lot' to do, I would buy a cheap dowelling jig such as this,
Milescraft JointMate Dowelling Jig
The Milescraft JointMate is a universal dowel jig for creating quick and accurate corner, edge and surface joints with ease.
I have had some success with these simple jigs.
I believe Wolfcraft sell one similar in Europe?

wolfcraft 4641404 Dowel Quick Doweling Jig : Amazon.com.au: Home Improvement
wolfcraft 4641404 Dowel Quick Doweling Jig : Amazon.com.au: Home Improvement
www.amazon.com.au
I may not have grasped what you actually intend to do, so a quick diagram would help. Draw it and take a picture with your phone to post on the forum.