Changing colour of a Jpeg/photoshop logo

[thedoouge]

I have recieved a multi coloured logo in jpeg format. I converted it to a photoshop to achieve transparancy and desaturted it so that it is only greyscale. when I tried to replace the color in photoshop. I was unsure thatit was exactly pantone 194. I need to apply the logo to a letterhead but in a single colour. Is there a way of applying a pantone colour and tints of the sane colour to a photoshop file in Illustrator?
Thanks in advanve
The doouge

 

[jmgalvin]

Wouldn't it just be easier to replace the colors in photoshop and then bring it into illustrator?

Using OSX 10.3.9 on a G4

 

[xPox]

Use channels in photoshop to apply a spot color.