I'm pretty sure that conditions are the only thing in TellMeWhen for which you can use Lua code. Combat Event icons exist, but I don't think you can do any processing with them. Also, I don't see any way to output the value of a global variable from a DogTag
You could maybe...
Well, turns out you can. Here it is:
Code:
^1^T^SCLEUEvents^T ^SSPELL_CAST_SUCCESS^B ^t^SType^Scleu ^SCLEUDur^N0 ^SName^S146059 ^SEvents^T ^N1^T ^SType^SLua ^SLua^S--~`Reset~`Multistrike~`Count~J local~`icon~`=~`...~J ~J icon.msCount~`=~`0~J ~J icon:SetInfo(~J ~`~`~`"stack,~`stackText",~J ~`~`~`nil,~`nil~J ) ^SEvent^SOnRightClick ^SPassThrough^b ^t^N2^T ^SType^SLua ^SLua^S--~`Initialize~`Multistrike~`Count~M~J local~`icon~`=~`...~J ~J if~`not~`icon.msCount~`then~J ~`~`~`icon.msCount~`=~`0~J end ^SEvent^SOnEventsRestored ^t^N3^T ^SType^SLua ^SLua^S--~`Increment~`Multistrike~`Count~M~J local~`icon~`=~`...~J ~M~J icon.msCount~`=~`icon.msCount~`+~`1~M~J ~M~J icon:SetInfo(~M~J ~`~`~`"stack,~`stackText",~M~J ~`~`~`icon.msCount,~`icon.msCount~M~J ) ^SEvent^SOnCLEUEvent ^t^N4^T ^SType^SLua ^SLua^S--~`Reset~`Multistrike~`Count~M~J local~`icon~`=~`...~J ~J icon.msCount~`=~`0~J ~J icon:SetInfo(~J ~`~`~`"stack,~`stackText",~J ~`~`~`nil,~`nil~J ) ^SEvent^SOnCondition ^SOnConditionConditions^T ^N1^T ^SType^SCOMBAT ^SLevel^N1 ^t^Sn^N1 ^t^t^Sn^N4 ^t^SSettingsPerView^T ^Sicon^T ^STexts^T ^N1^S[Stacks:Hide(0)] ^N2^S ^t^t^t^SShowWhen^N3 ^SCustomTex^Sinv_jewelry_orgrimmarraid_trinket_13 ^SSourceUnit^Splayer ^SEnabled^B ^t^N62602^S~`~| ^Sicon^^
I'm assuming that Multistrike gets cast in a standard way when it procs.
The number of procs goes into [Stacks], so you can move that around by messing with layouts; I didn't do any of that.
When you go from in-combat to not-in-combat, the stack count is reset to zero.
If you want to manually reset the stack count for any reason, right click the icon.