cutting off digits and rounding up/down

[Streen]

I am looking for a function in visial basic.net that takes a string, containing a decimal, like 12.5958, and returns the string with x numbers of digits behind the comma with appropriate rounding.

like x = 3 --> 12.596
and x = 2 --> 12.60

I can write it myself, but I am hoping its out there already, savingme the time.

thanks