The phrase "somehow useful" is correct and usable in written English.
You can use it to indicate that something has some usefulness, even if it may not be immediately apparent. For example: "This old book may seem irrelevant, but it's somehow useful if you look at it from a different perspective."
But there is something about thinking that there's something I'm trying to say – that I have a myth – that's always felt somehow useful to me.
Mr Musharraf's trials may not have much impact on the coming elections, but could serve as somehow useful to the army in the post-election period.
Some so-called topoi of the Rhetoric belong neither to the specific nor to the common class, but are just instructions or patterns that are somehow useful in public speech.
"Very often the ill person doesn't get over the disease, and his death is somehow useful to the plot's outcome," Dr. Luciano De Fiore said in a statement.
Shanzhai is a new area of interest that the Western design and art world want to figure out and make somehow useful.
The letter even questions the police's motives: "It is therefore not unreasonable to consider whether the police see these violent men as somehow useful to their efforts to scare women off the streets".
If scientists could somehow use the Wnt protein to promote muscle development and discourage fat cells, he says, it might eventually be useful for treating obese patients who have more fat cells than normal.
There are millions of you ― of us ― searching for uneasy answers, trying not to breakdown on the subway, forcing ourselves to pull our shirts over our heads and attempt to somehow be useful in a country that seems to have no use for us, in a country that we are certain does not want us, that we worry will not keep us safe.
"I just hope they will somehow be useful in the future".
The result is a fairly clear, mess-free stream of rumors and trade information that some obsessed trader types may somehow find useful.
Under Catalan's influence, Cesàro initially referred to the "conventional formulas" for 1 − 2n + 3n − 4n +... as "absurd equalities", and in 1883 Cesàro expressed a typical view of the time that the formulas were false but still somehow formally useful.
