NextGEN Gallery image set spacing

Hi, I use NetGen Gallery on my photography web site. I couldn’t do without it these days and so will be making a donation. I’ll often add a set of images in a horizontal row adjusting their common height until the set is ~ 520 wide. Could this be automated so that I can add an image set with something like this:

[multipic ids=917,918,919 w=520]

Having the PHP code do the heavy lifting of working out the exact height needed to get the perfect width would save me a lot of time.

Mark