[TYPO3] including typoscript

[Bas Heutink]

Hi group,

Just a simple question. I want to include a typoscript file from an 
already included typoscript file.

So from the template/setup I include the basis template:
<INCLUDE_TYPOSCRIPT: source="FILE: fileadmin/templates/xyz/ts/ts_xyz.txt">

 From fileadmin/templates/xyz/ts/ts_xyz.txt I include the menu structure:
<INCLUDE_TYPOSCRIPT: source="FILE: 
fileadmin/templates/xyz/ts/ts_menustructuur.txt">

Problem: I can include from the template/setup but not from an already 
included file. How can I resolve this?

Regards, Bas