Hi Indre Sim,
A company resident in the UK is generally liable to corporation tax on its worldwide income.
Any trading activities that are conducted through the limited company will be within the charge to UK tax.
In respect of tax deducted in Denmark the conditions of exemption or relief can be found in the relevant Double Taxation treaty.
Further information can be found in HMRC'S international manual.
INTM167000 - UK residents with foreign income or gains: corporation tax
Thank you.