can you turn a visible laser pointer into a uv one?
Lasers can be frequency doubled using nonlinear media. However, the process is not simple, and typically requires precise alignment and materials engineered for the specific wavelength or else extremely high power.
In spite of the cost, this method is used to double 532nm lasers to generate 266nm (or in reality to quadruple 1064nm lasers). For longer near-UV wavelengths, it's usually cheaper to buy a direct UV source. There are fairly cheap laser diodes above 350nm.