drilling a stocks forend straight from right to left?

OK , I need some advise,
I have this beautiful very slim type Maple Mannlicher stock that someone custom made. Its flawless, mated to an early Sako barreled action.
Its only flaw was the use of a Winchester model 94 barrel band at the mid point of the forend.
It fit OK but had no business being on a Mannlicher stock and although the barrel channel was completely glassed it is not free floated and the barrel band just adds to its rigidness.
I have thought and thought about how to correct this injustice.
I decided to make a Sling stirrup and place it at this junction to help with the 2 screw holes that were used for the barrel band because the checkering is accented on each side of the band and that way I can do away with all traces of the barrel band and open up the barrel channel to float its barrel.
Ok my build on the stirrup as I have done so in the past is to use a 7/32 4140 welding rod for the stirrup and and bend 2 90s on it that just missies the edges of the wood but only After I heat and flatten and shape the 2 endos of the stirrup on to drill for a 6x32 oval headed screw and the other end to be tapped for the screw. but my problem is this
The 2 holes in the sides of the forend are of 2 different sizes of wood screws which only barley miss the glassed barrel channel.
But I need to enlarge the holes but only on the bottom part of the holes ( to miss the barrel channel)and it needs to be straight across the stock forend as to end up at the other hole, right now they are blind screw holes, and I need to enlarge them for a steel tube to be installed to be glassed in just proud of the wood to give the sling the desired swing and keep from pinching the wood.
So is there a jig or tool I could fabricate that would allow me to drill such an accurate hole and get it where it just clears the top part of the larger hole.
Or maybe just get a couple slugs or Crown Royal and my Craftsman cordless drill and my best bit and have at it?
Ron

The way to do this is with a milling machine which can hold the stock in the right position and can drill holes using small end mills that will cut straight instead of following the old hole.

This may not be within your range of options. If all you have are hand tools, start with a small rattail file and true the path and location of the cross hole.

I would stay away from 6-32 screws; use a 6-40 or a 6-48 (if you can find one long enough, or make one) so you have some threads in the tapped side of your sling swivel.

A simple drill jig can be fabricated in the form of a yoke with aligned holes drilled through both sides. Align the yoke's holes with the stock's existing holes and drill through from each side.

What machinery and tools do you have available to you? If you have a drill press or mill things will be easier. An end mill can be held in a drill press chuck for a straight drilling operations, but not for any operation that causes sideways pressure on the chuck. The stock can then be clamped to a square block fastened to the table, at the barrel channel surface. This should allow you to line up everything. On some jobs there is sometimes more work in the setup than the actual operation.

Thank you guys for all the answers,
Yes I have a far east bench mill.
I will use that , It has a heavy old Kurt vise mounted to the table. I am sure I have an end mill that will fit any tube I make
Like you said it will take more set up than the actual drilling.
As I see it now the forend should only be leveled along its centerline, other than that I just have to position the table to where the hole should be cleaned up. forward or backward and left and right.
Thanks
Ron

This thread is an inspiration to finally get around to drilling that aftermarket "sportster" stock that is fitted to the SKS.

The issue stock has a shaped thru bolt lug that takes the recoil ahead of the receiver. The aftermarket piece skips that element.

I've got the lug, just needed a push to come up with a scheme to drill it in the correct position.
I'll make up a drill jig that registers off the barreled action. Should work a treat!

Of course, Even with thousands of rounds fired. The present stock has shown no weakness. Laminated wood must be tougher than "Asian mystery wood" . ;-)