Dynamics with attributes aligned on dynamic sign (e.g. "poco f" aligned on "f")

Dynamics like "poco forte" should be aligned on the "forte". In this snippet we define a markup command to align a line-markup on the center of the second. Then we define a new dynamic-script with attributes. Now "poco/meno/silly" "forte" is aligned on "forte". X-offset is tweaked to 0, because otherwise markup halign will not work and so overriding will have no effect. But you can use extra-offset to move the DynamicText.