Problem with alignment of elements within a QGridLayout

[qwasder85]

Please have a look at the picture showing my QGridLayout below. Blue are widgets, magenta shows my grid layout. The two green "buttons" are in a QHBoxLayout within a QFrame.
I want those two buttons to align right within that first column without them stretching that column.

Using insertStretch(0) on the QHBoxLayout or setting the buttons to Qt::AlignRight both stretches the column.
I feel like this can be solved with a correct QSizePolizy, but I can't find a working combination.

(The "^ Stretch v"-text has nothing to do with the issue btw.)