Function 77 for Cleartype

Hello,

I am hinting Devanagari font using VTT and have 1 problem with cleartype only deltas (function 77). As I understand it is enough to change the definition of function 84 to make function 77 work for cleartype as for greyscale. I tried to do this but my knowledge is not enought - the change of value to 8192 is not enough, other selectors also must be changed.

By defoult the definition of 84 is such -

FDEF[],84
#BEGIN
#PUSHOFF
#PUSH,2,0
WS[] /* s[2] = grey scaling: off (by default) */
#PUSH,35,1 /* 35 = MS Rasterizer version 1.7 */
GETINFO[] /* 1 = tell GETINFO to give us the rasterizer version */
LTEQ[] /* 35 <= version ? */
#PUSH,64,1 /* 64 = highest rasterizer version assigned to MS */
GETINFO[] /* 1 = tell GETINFO to give us the rasterizer version */
GTEQ[] /* 64 >= version ? */
AND[] /* 35 <= version && version <= 64 ? */
IF[] /* if so, we’re running MS rasterizer version 1.7 or higher */
#PUSH,4096,32 /* 4096 = flag returned by GETINFO if grey scaling bit is on */
GETINFO[] /* 32 = tell GETINFO to give us the grey scaling bit */
EQ[] /* 4096 == flag ? */
IF[] /* if so, we’re running under grey scaling */
#PUSH,2,1
WS[] /* s[2] = grey scaling: on (by now) */
EIF[]
EIF[]
#PUSHON
#END
ENDF[]

In glyph program function 77 is written in this way - CALL[], 33, 64, 11, 2, 77 but visually do not take any effect.

Maybe somebody can help me - what must be changed in this definition to make function 77 work for cleartype?